DE3927353A1 - Image forming member for electrophotography - Google Patents

Abstract

Member has at least a photoconductive layer and a surface layer on a base. The photoconductive layer is composed of non-monocrystalline silicon including 1 10 at % of H and 5 15 at % of C, and having 0.01 0.05 ratio of expansion mode of C-H bond and that of Si-H bond by infrared ray absorbing spectral, and has the layer structure not including graphite structure, or including less than 1% of graphite structure per unit vol. The surface layer is composed of non-monocrystalline silicon carbide including 50 70 at % of H and 20 40 at % of C, and has the layer structure not including the graphite structure of including less than 1 % of graphite structure per unit vol. The charge injection preventing layer is formed between the base and the photoconductive layer.

Description

The present invention relates to an electrophotographic Image forming material with a photoconductive layer of one Non-single crystal silicon carbide material, the silicon atoms as a matrix, Hydrogen atoms in an amount of 1 to 10 atomic% and carbon atoms contains in an amount of 5 to 15 atomic% and in an infrared Absorption spectrum an intensity ratio between the C-H Bond stretch mode and the Si-H bond stretch mode of 0.01 has up to 0.05. (The expression "non-single crystal silicon carbide material" is said to be amorphous silicon carbide material including microcrystalline and polycrystalline silicon carbide material).

So far, various proposals have been made for an electrophotographic Image forming material with a photoconductive layer made of an amorphous silicon carbide. For example, in the US-PS 45 39 283 a photoconductive material with an amorphous silicon layer  indicated the carbon atoms in the direction of the layer thickness contains in an uneven distribution. In the US PS 46 77 044 becomes a light-sensitive material with a charge transport layer from an amorphous silicon carbide, a charge generation layer made of an amorphous silicon and a surface modification layer specified from an amorphous silicon carbide. In the US PS 46 73 629 is a photoreceptor with a charge transport layer an amorphous silicon carbide, a charge generation layer an amorphous silicon, a surface modification layer an amorphous silicon carbide and an intermediate layer of one amorphous silicon carbide specified.

It is known that these known amorphous silicon carbide films according to a conventional chemical high-frequency plasma vapor deposition process (short RF-PCVD procedure) in the same way as for the production of a hydrogenated amorphous silicon film according to the above RF-PCVD processes can be produced.

In comparison with the known hydrogenated amorphous silicon films all known amorphous silicon carbide films are more affected with a view to being more or less not just by hydrogen atoms contingent defects, but also others, on double bonds deficiencies due to carbon atoms. Although further the known silicon carbide films have a high dark resistance show, they are problematic in that built in the films Carbon atoms increase depending on the location of these atoms of the tail state on the side of the line tie can, which leads to a decrease in electron mobility. In this regard, there are known amorphous ones for use Silicon carbide films as a constituent layer of an electrophotographic Image forming material a limit.

The electrophotographic properties of the known electrophotographic Imaging materials with a photoconductive Layer of a known amorphous silicon carbide were mostly against a light source with long-wave light, such as a tungsten halogen lamp, considered. Their practically applicable properties have been  evaluated on photocarriers as a result of the absorption of long-wave Light emerged as a whole through its photoconductive layer.

The well-known electrophotographic image forming materials with a photoconductive layer made of an amorphous silicon carbide are mostly such that they have an amorphous silicon carbide layer and have a charge generation layer under or on top of it, wherein a charge generated in the charge generation layer (photo carrier) injected into said layer of amorphous silicon carbide to form a latent electrostatic image. These known electrophotographic image forming materials have usually been considered practical for as long as at least electrons or holes in their amorphous silicon carbide layer have a sufficient support area.

So can be said of the known amorphous silicon carbide films be that they are practical in the case where they are used as photoconductive Layer of photosensitive imaging material for a normal speed electrophotographic copier system or serve a printing system of normal speed.

None of the known electrophotographic imaging materials with a constituent layer made of an amorphous silicon carbide film is sufficient, however, to meet all requirements for an electrophotographic Image forming material in an electrophotographic High speed copying system using a coherent Laser light beam as a light source or in a high-speed printing system to suffice.

If e.g. B. a known electrophotographic image forming material with a photoconductive layer from a known amorphous Silicon carbide film in the high speed electrophotographic copying system is used and the electrophotographic Image formation process including corona charging and exposure processes repeated for some time, occur as a result of repeated corona charging at high speed frequently on the Material pinholes (pinholes) on, leading to the formation of faulty images  leads. In this case also appear on the copies made often ghosting.

The electrophotographic image forming method in the aforementioned high speed electrophotographic copying system also relatively complicated if you go at high speed repeatedly want to produce high quality images. A problem of the known electrophotographic image forming materials with amorphous Silicon carbide when used in this complicated electrophotographic Image formation process is that because of the repeated Corona charging at high speed is a dark decay can occur.

Furthermore, in the aforementioned electrophotographic image forming process the corona charge, image exposure, development, Image transfer and cleaning at high speed continuously repeated, and a pre-exposure to eliminate the Residual potential made that from the previous image pattern Carrying out the corona charging resulted. When using the electrophotographic Image forming material with the aforementioned known amorphous silicon carbide system in this image formation process there is the problem that electrons or holes in their photoconductive Layer due to the aforementioned pre-exposure in large quantities can be captured. These electrons once captured and Holes in the photoconductive layer are exposed during corona charging and cause a drop in the surface electrical potential, resulting in a growing disintegration in the image forming material leads. In this case, another problem is that these electrons trapped in the photoconductive layer and Holes with electrons and generated during image exposure Holes can recombine, causing a drop in photosensitivity of the image forming material.

If the known amorphous silicon carbide film according to a conventional RF-PCVD process is formed, one problem is that at a deposition rate of 80 Å / s or more the electrical properties of the resulting amorphous silicon carbide film  deteriorate significantly.

If the known electrophotographic image forming material with the photoconductive layer made of a known silicon carbide film and a surface layer laminated on the photoconductive layer in the aforementioned high performance electrophotographic copying system charge retention is also used comparatively compared to the embodiment without any surface layer satisfactory. But since the rotation cycle is short, is the electrical surface potential due to the repeated Corona charges gradually degrade, causing an appearance will, the "drop in electrical surface potential" is called. The appearance of this phenomenon is different in Depends on the degree between the part of the photoconductive Layer that has been irradiated with light and the remaining part that has not been exposed to light. This causes the appearance of one clear ghost image on the preserved image.

To create an electrophotographic image forming material a charge injection inhibitor layer has proven to be effective to inject a charge from the substrate side into the photoconductive layer to prevent. An electrophotographic imaging material with a substrate and a light-receiving layer from a charge injection inhibition layer and a photoconductive Layer of a known amorphous silicon carbide film in this Order are laminated onto the substrate when in use in the aforementioned high speed electrophotographic copying system the problem of pinholes on the image forming material can occur because of the electrophotographic image forming process is repeated constantly at high speed and the associated conditions including the loading conditions may be hard.

Against this background, it should be borne in mind that electrophotographic High speed copier systems gradually becoming largely come into use. There is a growing demand for creation an inexpensive, desirable electrophotographic image forming material, that are the requirements for such high-performance copier systems  sufficiently fulfilled and the desired functions as an electrophotographic image forming material therefor Systems permanently shows by doing an amorphous silicon carbide film used and its various advantages are exploited.

The present invention aims to eliminate the aforementioned Problems of electrophotographic image forming materials with the conventional amorphous silicon carbide system and on creating an inexpensive and improved electrophotographic Image forming material with a non-single crystal silicon carbide system, this material in continuous electrophotographic High speed copier systems with a coherent laser light beam can be used as a light source and the above Requirements met without the aforementioned problems.

An improved electrophotographic image forming material is also said with a light receiving layer made of a specific Non-single crystal silicon carbide film can be created, the excellent electrical properties and a sufficiently long carrier area for electrons and holes, even at high deposition rates, d. H. 80 Å / s or more can be consistently achieved can.

Furthermore, according to the invention, an improved electrophotographic Image forming material of the non-single crystal silicon carbide system be created in which the above problem of pinholes does not occur in electrophotographic Image forming materials with the known amorphous silicon carbide systems can be observed.

An improved electrophotographic image forming material is also intended based on the non-single crystal silicon carbide system be created that the repeated constant reproduction desired Allows images without the accompaniment of ghost images.

Finally, an improved electrophotographic image forming material of the single crystal free silicon carbide system  with no drop in the surface potential occurs in the known electrophotographic image forming materials with the amorphous silicon carbide system with repeated Loading and image exposure is observed, and the one repeated and constant reproduction of desired images also with Use in the aforementioned electrophotographic high-performance copying system enables.

This object is achieved by the present invention includes the following four representative embodiments.

According to the first embodiment of the invention, an electrophotographic Image forming material with a substrate and created a light receiving layer arranged on the substrate, wherein the light receiving layer is a photoconductive layer made of a Has non-single crystal silicon carbide film, the silicon atoms as Matrix, carbon atoms in an amount of 5 to 15 atomic% and hydrogen atoms in an amount of 1 to 10 atomic% and graphite structure- Contains districts in a proportion of 1% or less per unit volume and an intensity ratio in the infrared absorption spectrum between the C-H bond stretch mode and the Si-H bond stretch mode from 0.01 to 0.05.

According to the second embodiment of the invention, an electrophotographic Image forming material with a substrate and created a light receiving layer arranged on the substrate, wherein the light receiving layer is a charge injection inhibiting layer and a photoconductive layer that is put on the side in that order of the substrate are stacked, and the charge injection inhibiting layer and the photoconductive layer made of a non-single crystal Silicon carbide film are formed, the silicon atoms as a matrix, carbon atoms in an amount of 5 to 15 atomic%, hydrogen atoms in an amount of 1 to 10 atomic% and graphite structure areas in one Contains 1% or less per unit volume and in the infrared Absorption spectrum an intensity ratio between the C-H Bond stretch mode and Si-H bond stretch mode from 0.01 to Has 0.05.  

According to the third embodiment of the invention, an electrophotographic Image forming material with a substrate and created a light receiving layer arranged on the substrate, wherein the light receiving layer is a photoconductive layer and a Has surface layer in that order on the side of the substrate are layered, the photoconductive layer a non-crystal silicon carbide film is formed, the silicon atoms as a matrix, carbon atoms in an amount of 5 to 15 atom%, Hydrogen atoms in an amount of 1 to 10 atom% and graphite structure Districts in a proportion of 1% or less per unit volume contains and in the infrared absorption spectrum an intensity ratio between the C-H bond stretch mode and the Si-H bond stretch mode from 0.01 to 0.05, and the surface layer a non-crystal silicon carbide film is formed, the silicon atoms as a matrix, carbon atoms in an amount of 20 to 40 atom%, Hydrogen atoms in an amount of 50 to 70 atomic% and graphite structure- Districts in a proportion of 1% or less per unit volume contains.

According to the fourth embodiment of the invention, an electrophotographic Image formation material created that over the the features of the image forming material of the third embodiment the invention further a charge injection inhibitor layer between the substrate and the photoconductive layer, these Charge injection inhibitor layer made of a non-single crystal silicon carbide film is formed, the silicon atoms as a matrix, carbon atoms in an amount of 5 to 15 atomic%, hydrogen atoms in one Amount of 1 to 10 atomic%, atoms of a group III element or Group V of the Periodic Table and Graphite Structure Districts in a proportion of 1% or less per unit volume and an intensity ratio in an infrared absorption spectrum between the C-H bond stretch mode and the Si-H bond stretch mode from 0.01 to 0.05.

All of the aforementioned representative electrophotographic imaging materials The invention surpasses the known electrophotographic Imaging materials of the amorphous silicon carbide system  in terms of their electrophotographic properties and are free from cargo retention problems, the dark decay, the sensitivity to light, the appearance of phantom images etc. used in electrophotographic Image forming materials of the known amorphous silicon carbide system are to be found.

All of the aforementioned representative electrophotographic imaging materials of the invention are for use in one high performance electrophotographic copying system, thereby the continuous and constant reproduction of desired images without the mentioned problems of pinholes, waste of the surface potential, etc., which is possible with the known electrophotographic image forming materials of the amorphous Silicon carbide systems can be found if they are in one electrophotographic high-performance copier system with continuously repeated Can be used for a long period of time.

Fig. 1 (A) to 1 (D) are schematic cross-sectional views illustrating the representative embodiment of the electrophotographic image forming material according to the invention.

Fig. 2 shows the optical attenuation curves of the surface electric potential in response to the lapse of time under positive loading on an electrophotographic image-forming material with the known amorphous Siliziumcarbidsystem.

Fig. 3 shows the optical attenuation curves of the surface electric potential in response to the lapse of time under adverse loading on an electrophotographic image-forming material with the known amorphous Siliziumcarbidsystem.

FIG. 4 shows the optical attenuation curves of the electrical surface potential as a function of the time course under positive loading in the case of an electrophotographic image-forming material of the non-single-crystal silicon carbide system according to the present invention.

Fig. 5 shows the optical attenuation curves of the surface electric potential in response to the lapse of time under adverse loading on an electrophotographic image-forming material of the non-single-Siliziumcarbidsystems according to the present invention.

Fig. 6 (A) is a schematic longitudinal section, partially broken away, of a microwave plasma chemical vapor deposition apparatus (hereinafter referred to as "MW-PCVD apparatus") which is used to manufacture an electrophotographic image forming material of the non-single crystal silicon carbide system of the invention using the Microwave plasma process of chemical vapor deposition (hereinafter referred to as "MW-PCVD process") is suitable.

Fig. 6 (B) is a schematic partial section of the MW-PCVD apparatus shown in Fig. 6 (A).

Fig. 7 is a schematic longitudinal section, partially broken away, of an apparatus for producing an electrophotographic image forming material of the amorphous silicon carbide system by means of a high-frequency glow discharge decomposition method of the comparative examples described later.

Fig. 8 (A) and FIG. 8 (B) are schematic explanatory views of a method for the evaluation of the resultant image-forming materials of Examples and Comparative Examples described later.

FIG. 9 shows optical damping curves for an electrical surface potential as a function of the time course with a negative loading of the electrophotographic image-forming material formed in the example described later.

FIG. 10 shows optical damping curves for an electrical surface potential as a function of the time course with a positive loading of the electrophotographic image-forming material formed in the example described later.

Representative embodiments of the electrophotographic Image forming material of the invention will now be referenced explained in more detail on the drawings. The description is intended to cover the scope of the invention not restrict.

Representative electrophotographic image forming materials of the invention are shown in Figs. 1 (A) through 1 (D), in which the substrate 101 , the photoconductive layer 102 , the charge injection inhibiting layer 103 and the surface layer 104 can be seen.

Fig. 1 (A) is a schematic representation of the typical layer structure of the electrophotographic image forming material according to the present invention, which comprises a substrate 101 for electrophotography and a light receiving layer having a photoconductive layer 102 on said substrate 101 , the photoconductive layer 102 being made of a non-single crystal -Silicon carbide film is formed which contains silicon atoms as a matrix, carbon atoms in an amount of 5 to 15 atom%, hydrogen atoms in an amount of 1 to 10 atom% and graphite structure areas in an amount of 1% or less per unit volume and in the infrared absorption spectrum has an intensity ratio between the CH bond stretching mode and the Si-H bond stretching mode of 0.01 to 0.05.

Fig. 1 (B) is a schematic representation of another representative layer structure of the electrophotographic image forming material of the present invention, which comprises a substrate 101 for electrophotography and a light receiving layer disposed on the substrate 101 , the light receiving layer being a charge injection inhibiting layer 103 and a photoconductive layer 102 which are stacked in this order from the side of the substrate 101 . The charge injection inhibiting layer 103 is formed of a p-type or n-type single crystal silicon-containing film, and the photoconductive layer 102 is formed of the same non-single crystal silicon carbide film as in the case of Fig. 1 (A). In a preferred embodiment, in this case, the charge injection inhibition layer 103 is formed of a non-single crystal silicon carbide film, the silicon atoms as a matrix, carbon atoms in an amount of 5 to 15 atom%, hydrogen atoms in an amount of 1 to 10 atom%, atoms of an element of Group III or Group V of the Periodic Table and graphite structure areas in a proportion of 1% or less per unit volume and in the infrared absorption spectrum an intensity ratio between the CH bond stretching mode and the Si-H bond stretching mode of 0.01 to Has 0.05.

Fig. 1 (C) is a schematic representation of another representative layer structure of the electrophotographic image forming material of the present invention having a substrate 101 for electrophotography and a light receiving layer disposed on the substrate 101 , the light receiving layer comprising a photoconductive layer 102 and a surface layer 104 which are stacked in this order from the substrate 101 side. The photoconductive layer 102 is formed from the same non-single crystal silicon carbide film as in the case of Fig. 1 (A), and the surface layer 104 is formed from a single crystal free film containing silicon. In the preferred embodiment of this case, the surface layer 104 is formed from a single crystal free silicon carbide film, the silicon atoms as a matrix, carbon atoms in an amount of 20 to 40 atom%, hydrogen atoms in an amount of 50 to 70 atom% and graphite structure areas in one Contains 1% or less per unit volume.

Fig. 1 (D) is a schematic illustration of another representative layer constitution of the electrophotographic image forming material of the invention, comprising a substrate 101 and, disposed on the substrate 101 light-receiving layer, wherein the light receiving layer comprises a charge injection inhibition layer 103, photoconductive layer 102 and a surface layer 104, which are laminated in this order from the substrate 101 side. The charge injection inhibition layer 103 is formed of the same film as the charge injection inhibition layer in the case of Fig. 1 (B). The photoconductive layer 102 is made of the same non-single crystal silicon carbide film as in the case of Fig. 1 (A). The surface layer 104 is made of the same film as the surface layer of Fig. 1 (C). In a preferred embodiment of this case, the charge injection inhibition layer 103 is made of a non-crystal silicon carbide film having silicon atoms as a matrix, carbon atoms in an amount of 5 to 15 atomic%, hydrogen atoms in an amount of 1 to 10 atomic%, atoms of an element of the group III or V of the periodic table and graphite structure regions in a proportion of 1% or less per unit volume and in the infrared absorption spectrum has an intensity ratio between the CH bond stretching mode and the Si-H bond stretching mode of 0.01 to 0.05 . The surface layer 104 is formed of a non-single crystal silicon carbide film, the silicon atoms as a matrix, carbon atoms in an amount of 20 to 40 atom%, hydrogen atoms in an amount of 50 to 70 atom% and graphite structure areas in an amount of 1% or contains less per unit volume.

Now the substrate and each constituent layer of the invention electrophotographic image forming material explained.

Substrate 101

The substrate 101 can either be electrically conductive or insulating for use in accordance with the invention. The electrically conductive substrate can comprise, for example, metal, such as NiCr, stainless steels, Al, Cr, Mo, Nb, Ta, V, Ti, Pt and Pb, or alloys of these metals.

The electrically insulating substrate can comprise, for example Films or sheets made of synthetic resins, such as polyester, polyethylene, Polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, Polystyrene, polyamide, glass, ceramic or paper. The electrically insulating substrate is preferably at least one of its surfaces undergoes a treatment to achieve electrical Subjected to conductivity and on the surface thus treated with provided a light receiving layer.

In the case of glass, for example, the electrical conductivity achieved by having a thin surface Film made of NiCr, Al, Cr, Mo, Au, Ir, Nb, Ta, V, Ti, Pt, Pd, In₂O₃, SnO₂, ITO (In₂O₃ + SnO₂), etc. orders. In the case of the synthetic Resin films such as B. a polyester film, the electrical conductivity applied to the surface by making a thin one  Metal film such as NiCr, Al, Ag, Pv, Zn, Ni, Au, Cr, Mo, Ir, Nb, Ta, V, Tl and Pt by vacuum deposition, electron beam deposition, Spraying, etc. or by coating the surface with the metal. The substrate can have any shape e.g. B. cylindrical, ribbon or plate-shaped shape, depending on the Use cases is chosen appropriately.

When using the electrophotographic image forming material according to FIG. 1 in continuous reproduction processes at high speed, it has, for. B. the shape of an endless belt or a cylinder.

The thickness of the substrate material is expediently determined in such a way that the electrophotographic image forming material is as desired can be brought into shape.

If the electrophotographic image forming material is flexible should be as thin as possible within an area be designed so that the substrate function sufficiently fulfills can be. The thickness is in terms of manufacturing and handling or the mechanical strength of the substrate in general larger than 10 µm.

The substrate surface may be uneven to prevent the occurrence of incorrect images due to so-called interference fringe patterns to exclude, which can occur in the pictures, if the Imaging process with coherent monochromatic light, such as laser beams, is carried out.

Photoconductive layer 102

It is an essential factor of the electrophotographic image forming material of the present invention that its photoconductive layer 102 is formed of a specific non-single crystal silicon carbide film in order to achieve the object of the present invention.

This specific non-single crystal silicon carbide film contains Silicon atoms as a matrix, carbon atoms in an amount of 5 to 15 atomic%, hydrogen atoms in an amount of 1 to 10 atomic% and Graphite structure districts in a proportion of 1% or less per unit volume and has an intensity ratio in the infrared absorption spectrum  between the C-H bond stretch mode and the Si-H bond stretching mode from 0.01 to 0.05.

The present invention has been found in extensive studies on a photoconductive layer made of a non-single crystal Silicon carbide material.

The inventors mainly have various studies about the optical damping process of an electrical surface potential a photoconductive layer of a non-single crystal Silicon carbide material in an electrophotographic imaging material carried out. This is commonly considered one of the most appropriate factors viewed to performance an electrophotographic image forming material.

The following are the findings of these studies Results described.

The inventors have the following approaches to optical attenuation the photoconductive layer under positive loading in the electrophotographic Image formation process made.

The primary photocurrent of positive holes in the photoconductive Layer can be expressed by the equation:

whereinJ _H the photocurrent through positive holes,L the thickness of the photoconductive Layer,  a mean mobilized distance of the positive Lochs,F the amount of light set ande the electrical Elementary charge is.

It is believed that the number of in the photoconductive Layer photo-excited positive holes according to the equation

is damped, where N _h (X) is the number of positive holes at location x in the photoconductive layer, W _{h is} the area of positive holes (equal to the product μ _h · τ _h E , where μ _{h is} the mobility of the positive hole, τ _{h is} the lifespan of a positive hole and E is the electric field) and NO _{h are} the number of primarily photoexcited positive holes.

In this context, the mean mobilized distance  to the spotx in the photoconductive layer by the equation are expressed:

It follows that the photocurrent J _h can be expressed by positive holes through the equation:

Further, if the light absorption in the photoconductive layer of the equation F = F ₀ exp (- α x) , where F ₀ is the amount of light irradiated, α the extinction coefficient and x is a certain position in the photoconductive layer, the photocurrent can pass through positive holes through the following equation (1) can be expressed:

In the same way, the current Je can be expressed by electrons by the following equation (2):

where We is the area of the electron (equal to the product μ _e τ _h E , where μ _{e is} the electron mobility, τ _{h is} the life of the electron and E is the electric field).

In view of this, the total current J can be expressed by the equation J = J _e + J _h .

According to the above, the total current J can be obtained by the equation where C is the volume of the photoconductive layer, v is the surface electric potential, and t is time.

Then the optical attenuation of the electrical surface potential on the photoconductive layer can be obtained by the following Equation (3):

where v ₀ is the electrical surface potential of the photoconductive layer.

Based on the above situation, the first was optical Damping curve for the electrophotographic imaging material with the photoconductive layer made of a known amorphous silicon carbide film checked in the comparative example described later 2 in which the high-frequency glow discharge Decomposition method was applied.

Measurement of optical attenuation on the electrophotographic obtained Image formation material was made according to the known Method described in Photographic Science and Engineering, Vol. 24, No. 5,  P. 25, Sept./Oct. 1980.

As a result, the optical damping curve under positive corona charging according to FIG. 2 and another optical damping curve under negative corona charging according to FIG. 3 were obtained.

From the two optical damping curves obtained, it can be seen that at a short wavelength used for the exposure Light the optical attenuation with positive corona charging is smaller than with the negative corona charge. It was assumed, that the electrophotographic image forming material against Light containing long-wave light, such as B. light off a tungsten halogen lamp, show normal optical attenuation would.

The results shown in Figures 2 and 3 were discussed based on equations (1), (2) and (3) above. As a result, it was assumed that the product of the mobility and the life of the positive holes (hereinafter referred to as " µτ product") is smaller than that of the electron mobility and life.

Similarly, optical attenuation was tested on an electrophotographic imaging material having a photoconductive layer made of a specific non-single crystal silicon carbide film prepared as Sample No. 011 in Example 1 described below, which corresponds to the electrophotographic imaging material of the invention. As a result, the optical attenuation curve shown in FIG. 4 under positive corona charging and the optical attenuation curve shown in FIG. 5 under negative corona charging were obtained.

The results shown in Figs. 4 and 5 were discussed based on equations (1), (2) and (3) above. As a result, it was found that the μτ product for positive holes is superior to that of the conventional photographic image forming material .

It is known that in a single crystal free silicon carbide film, such as B. an a-SiC: H film, contain hydrogen atoms serve to compensate for the unpaired bonds of the silicon atoms.  However, if hydrogen atoms in an excessive amount contained, these excess hydrogen atoms are likely to break the ties on what lead to the formation of three-dimensional Networks of silicon atoms and / or silicon and carbon atoms leads, whereby the strength of the film structure is reduced. It it is also known that the hydrogen atom bonded to the silicon atom serves a binding orbital near the top of the valence electron band and thus the forbidden bandwidth to enlarge. However, if hydrogen atoms are in excess Amount contained, these excess hydrogen atoms carry in addition to increasing the prohibited bandwidth still to create turbulence in the structure of the valence electron band at what, in turn, reduces mobility leads to positive holes in the valence electron band.

Along with the appearance of this turbulence in the structure of the valence electron band also increases the density of the final state (commonly referred to as the tail state) the side of the valence electron band. The increased final state not only acts as a trap for positive holes, but also as Recombination center and this has a remarkable negative Influence on the transport of the photoexcited carrier.

With a non-single crystal silicon carbide film like the a-SiC: H- Film, in addition to the above, there are other peculiar Difficulties. As is well known from organic chemistry there are many hybrid orbitals for carbon atoms in the bond, such as B. SP, SP², SP³ etc. It is also known that carbon atoms are in the most stable state if they have a graphite structure accept. In view of this, the amount of defects in the above non-single crystal silicon carbide film through the orbital influenced by an electron within the carbon atom is taken.

It has now been experimentally found to decrease the amount of defects in the resulting non-single crystal silicon carbide film fundamentally necessary for the carbon atoms in it is to be in the four-coordination state (SP³).  

The binding energy between the carbon atom and the hydrogen atom is also larger than that between the silicon atom and the hydrogen atom. With a non-single crystal silicon carbide film, like an a-SiC: H film, a large proportion of the hydrogen atoms remain in the film in the C-H bond state, and as a result Carbon atoms and silicon atoms often bond to one another hindered.

As a result, investigations were carried out on the proportions each constituent atom, the binding state of the hydrogen atoms and the bonding state of the carbon atoms on a non-single crystal Silicon carbide film, i. H. an a-SiC: H film.

As a result, it was found that the content of the hydrogen atoms in the resulting a-SiC: H film, preferably in the range from 1 to 10 atom%, especially in the range from 3 to 7 atom% lies.

The following facts were also found. If the Content of the hydrogen atoms is less than 1 atom%, the increases Number of non-paired bonds with silicon and carbon atoms are linked to the result that the resulting a-SiC: H film has a large amount of defects. If the Content of the hydrogen atoms exceeds 10 atomic%, do not increase only the defects on the side of the valence electron band, but also the proportion of hydrogen atoms bound to carbon atoms undesirable, and as a result, the desired three-dimensional network hardly formed. As a result, it is difficult to form the desired a-SiC: H film.

The following further facts were found experimentally. In the case of an a-SiC: H film, this is due to a silicon atom bonded hydrogen atom desires the so-called Si-H bond, where a hydrogen atom is bonded to silicon atom. As well is for the carbon atom bonded to the hydrogen atom a so-called C-H bond is desired in which a hydrogen atom is bound to carbon atom. For a desired a-SiC: H- Film, it is necessary that this in the infrared absorption spectrum an intensity ratio between the C-H bond stretching mode  and the Si-H bond stretching mode is from 0.01 to 0.05. Provided if these conditions are met, such an a-SiC: H- Film showing that unpaired bonds are sufficiently caused by hydrogen atoms are compensated and those with the hydrogen atoms in Related defects are negligible.

It was also found experimentally that to solve the problem of the invention the carbon content in the film is an essential one Factor is. On the basis of this finding and the above. Knowledge, that the carbon atom occupy a large number of electron bits defects are easily formed in an a-SiC: H film. It There have also been studies of the desired location in the film contained carbon atoms made. The result was found that if the carbon atoms under the silicon atoms without touching are evenly distributed among themselves, the resulting a-SiC: H film has desirable properties.

Regarding the carbon content in an a-SiC: H film is in Introduction to Percolation Theory by D. Stauffer by Tailor and Francis, Inc., 1985, indicated that there was an improvement of an a-SiC: H film as long as the film is around Contains 40 atomic% carbon atoms.

The results of the experimental studies on this have shown, however, that in such an a-SiC: H film with about Clusters containing 40 atom% carbon atoms are present and this a-SiC: H film is not that according to the present one Invention shows desired electrical properties. Further Studies have shown that the optimal content of carbon atoms, the properties of the resulting a-SiC: H film Solution of the invention task gives in the range of 5 to 15 atomic% lies. It was also found that it was for the desired electrical properties of the a-SiC: H film is necessary, the content the districts with graphite structure to a share of 1% or bring less per unit volume.

If, according to the inventors, the proportion of graphite-structured districts per unit volume exceeds 1% the resulting a-SiC: H film has an undesirably low dark resistance,  and the electrophotographic image forming material A photoconductive layer made of this a-SiC: H film can have a Reduce cargo retention. In this case the graphite structure districts are likely to become flaws, and when this happens, photo-excited carriers are hardly transported, so that the photosensitivity of the electrophotographic Image forming material is reduced.

From this it was concluded that to solve the problem of the invention the single crystal free silicon carbide film is a single crystal free one Silicon carbide is hydrogen atoms in a lot from 1 to 10 atomic%, carbon atoms in an amount from 5 to 15 atomic% and graphite structure districts in a share of 1% or contains less per unit volume and in the infrared absorption spectrum an intensity ratio between the C-H bond stretching mode and the Si-H bond stretching mode from 0.01 to Has 0.05.

Accordingly, the photoconductive layer 102 in the electrophotographic image forming material of the present invention is formed from the above-mentioned non-single crystal silicon carbide film.

The photoconductive layer 102 can be doped with a p-type or n-type dopant if necessary.

For example, if the photoconductive layer is p-conductive are intended to be atoms of a group III element of the periodic Systems in the aforementioned non-single crystal silicon carbide film built-in. If the photoconductive layer is n-type should be atoms of a group V element of the periodic Systems in the above non-single crystal silicon carbide film built-in.

Examples of these Group III elements are B, Al, Ga, In and T. Examples of Group V elements are P, As, Sb and Bi. Among these elements, B, Ga, P and As are particularly preferred.

The amount of the Group III or Group V element incorporated in the photoconductive layer is preferably in the range of 1 × 10 ^-2 to 10 ² atomic ppm, particularly in the range of 1 × 10 ^-1 to 10 atom -ppm, each as an effective amount.

The term "effective amount" in this case means a Proportion of the element that acts as a donor or acceptor. If so a donor and an acceptor built into the photoconductive layer the quantitative difference between the built-in amount of the donor and that of the acceptor of the effective one Doping amount.

As described above, the photoconductive layer can be through uniform installation of a group III or group element V have a single line type.

As an alternative, the photoconductive layer can have p-n junctions or p-i-n transitions, if you consider the type of in the photoconductive Layer built-in doping element during layer formation toggles.

The photoconductive layer 102 of the electrophotographic image forming material of the present invention may incorporate one or more kinds of atoms selected from the group consisting of oxygen atoms (O) and nitrogen atoms (N) so as to control the light absorption properties and / or the resistance value of the layer. A halogen atom type selected from the group consisting of fluorine atoms (F) and chlorine atoms (Cl) can also be incorporated in order to further improve the defect density.

The photoconductive layer 102 of the present invention can be placed directly on the substrate 101 as shown in Fig. 1 (A) to obtain a practical electrophotographic image forming material.

Alternatively, the electrophotographic image forming material of the invention may take any of the configurations shown in Figs. 1 (B) to 1 (D) in which the light receiving layer has a multi-layer structure including the above-mentioned photoconductive layer and one or more other layers.

In any event, the thickness of photoconductive layer 102 is an important factor in achieving the objectives of the invention. The thickness of the photoconductive layer must therefore be carefully determined so that the resulting electrophotographic image forming material obtains the desired properties. In view of this, the thickness of the photoconductive layer 102 is preferably 5 to 100 μm.

Charge injection inhibitor layer 103

In the electrophotographic image forming material of the invention, it is possible to interpose a charge injection inhibition layer 103 between the substrate 101 and the photoconductive layer 102 , as shown in Figs. 1 (B) and 1 (D), for side charge injection into the photoconductive layer 102 of the substrate 101 to be prevented, whereby the electrophotographic properties are further improved.

This charge injection inhibition layer can be made of a non-single crystal Silicon-containing film can be formed, such as an amorphous silicon-containing film, a non-single crystal Silicon oxide film, a non-single crystal silicon nitride film or a non-single crystal silicon carbide film that is one element is doped, which controls the valence electron.

In the preferred embodiment, the charge injection inhibition layer 103 is formed from a non-single crystal silicon carbide film that hydrogen atoms in an amount of 1 to 10 atom%, carbon atoms in an amount of 5 to 15 atom%, atoms of an element capable of controlling the valence electron and structured graphite Contains areas in a proportion of 1% or less per unit volume and has an intensity ratio between the CH bond stretching mode and the Si-H bond stretching mode in the infrared absorption spectrum of 0.01 to 0.05.

In the above case, the charge injection inhibition layer is said to have the following effects.

Since there is a small amount of the defect in the above-mentioned non-single crystal silicon carbide film for forming the photoconductive layer 102 and also in the above-mentioned non-single crystal silicon carbide film which contains a valence electron controlling element for forming the charge injection inhibiting layer 103 , the charge injection is from the substrate side 101 extremely low due to the defect concentration, and the loading properties are significantly improved.

If an electrophotographic image forming material in an electrophotographic high-performance copying system where the amount of corona charge is increased and the electrophotographic Image forming material with one Charge injection inhibitor layer made of a known amorphous silicon carbide film with an element controlling the valence electron, and a photoconductive layer made from a known amorphous silicon carbide film is the charge injection by the defect level very considerable, and the injected charges are with the effect of the electric field accelerated by the corona charge and receive an excess energy. These injected Charges with excess energy come with the missing parts and / or the lattice points in the film in mutual contact and excite the charges trapped in the defects, causing the charges gliding in the edge as if on snow will. As a result, a strong electric current flows into the Photoconductive layer and thereby caused on the electrophotographic Image forming material local pinholes.

On the other hand, there is the electrophotographic image forming material the invention a minor opportunity for that Occurrence of these pinholes because of the material of few imperfections is accompanied even if, as mentioned above, in these high performance electrophotographic copier systems becomes.

The above-mentioned specific non-single crystal silicon carbide film for forming the photoconductive layer 102 and optionally the charge injection inhibiting layer 103 in the electrophotographic image forming material of the invention is one which has small defects and in which silicon atoms and carbon atoms are firmly bonded, and consequently a pin hole is hardly caused. Like the photoconductive layer 102 , the charge injection inhibiting layer 103 can be adjusted to be p-type or n-type by incorporating atoms of a Group III element or atoms of a Group V element in the layer.

Examples of Group III elements for hiring Conduction of the charge injection inhibitor layer to the p-type are u. a. B, Al, Ga, In and Tl. Examples of Group V elements that adjust the line of the charge injection inhibitor layer to the n-type, are u. a. P, As, Sb and Bi. Among these elements are B, Ga, P and As are particularly preferred.

The amount of the Group III and Group V element that is incorporated into the charge injection inhibitor layer is preferably in the range of 2 × 10² to 1 × 10⁴ atomic ppm, in particular in the range of 3 × 10² to 5 × 10³ atomic ppm, each as effective amount.

The meaning of the effective amount is the same as that of the above-mentioned photoconductive layer.

The charge injection inhibiting layer 103 may contain a kind of halogen atoms selected from the group of fluorine atoms (F) and chlorine atoms (Cl) with the purpose of reducing the defect density of the film and also improving the film durability when the film is made of the aforementioned specific non-single crystal silicon carbide . When the charge injection inhibiting layer 103 has one of the above films excluding the specific non-single crystal silicon carbide film, it may contain hydrogen atoms (H) and / or a kind of halogen atoms from the group consisting of fluorine atoms (F) and chlorine atoms (Cl).

In all cases of these cases, the amount is in the charge injection inhibitor layer Halogen atoms to be installed preferably in in the range of 10 atomic ppm to 5 atomic%. If hydrogen atoms (H) are incorporated, their amount is preferably in the range from 1 to 40 atomic%.

All component atoms of the charge injection inhibition layer, i.e. H. Silicon atoms (Si), carbon atoms (C), oxygen atoms (O), Nitrogen atoms (N), hydrogen atoms (H), group III atoms, Group V atoms, fluorine atoms (F), chlorine atoms (Cl) are fundamental contained in a uniform concentration in the layer.  Certain atoms can, however, in their concentration in the layer areas to be graded so that a predetermined Concentration distribution is guaranteed.

A preferred embodiment of the electrophotographic image forming material having the photoconductive layer 102 and the charge injection inhibiting layer 103 has the structure shown in Fig. 1 (B) or 1 (D).

Alternatively, a suitable layer may be disposed between the substrate 101 and the charge injection layer 103, which ensures the adhesion between the charge injection inhibition layer 103 and the substrate 101, or, if necessary, an absorption layer for light of long wavelength.

The thickness of the charge injection inhibiting layer 103 should be appropriately determined in view of the relationship with the thickness of the photoconductive layer 102 and other reference factors.

In general, however, it is preferably in the range from 1000Å to 10 µm.

Surface layer 104

In the electrophotographic image forming material of the invention, a surface layer 104 may be placed on the photoconductive layer 102 as in Fig. 1 (C) or 1 (D) to avoid charge injection into the layer on the free surface side of the photoconductive layer and the photoconductive To protect the layer from mechanical and / or chemical damage.

The surface layer 104 can be formed from a suitable translucent film without substantial photoconductivity, such as e.g. A non-single crystal silicon oxide film, a non-single crystal silicon nitride film or a non-single crystal silicon carbide film containing carbon atoms in a relatively large amount.

In a preferred embodiment, surface layer 104 is formed from a non-single crystal silicon carbide film that contains silicon atoms as a matrix, carbon atoms in an amount of 20 to 40 atomic percent, hydrogen atoms in an amount of 50 to 70 atomic percent, and graphite structure regions in one portion of 1% or less per unit volume.

The surface layer 104 according to the preferred embodiment of the invention shows the following effects.

If an electrophotographic image forming material with a surface layer of a known translucent amorphous silicon carbide film without significant photoconductivity on a photoconductive layer made of a known amorphous silicon carbide film, that of the above translucent amorphous silicon carbide film different, is laminated on, often shows a phenomenon that is commonly referred to as "drop in electrical surface potential" is designated and by imperfections near the free surface of the photoconductive layer and also is caused by defects in the surface layer. The appearance this phenomenon is probably caused by that charges near the interface between the photoconductive layer and the surface layer are captured and this trapped charges the distribution of the electric field change near the interface and so the charge injection into the photoconductive layer from the free surface side of the Promote surface layer.

The appearance of the drop in the surface electrical potential probably depends on the deep state in that prohibited band together, that in the well-known amorphous silicon carbide film is present.

The above phenomenon of the challenge of a drop in the surface electric potential is not a problem when this electrophotographic image forming material is used in a normal speed electrophotographic copying system. However, it is very problematic when this electrophotographic image forming material is used in a high-speed electrophotographic copying system in which the negative influences caused by the above-mentioned phenomenon are clearly apparent. In the electrophotographic image forming material of the present invention, the appearance of a drop in the surface electric potential as found in the prior art is not observed. The desired charge retention is effectively demonstrated even when the material is used in a high performance electrophotographic copying system, because the above-mentioned specific non-single crystal silicon carbide film forming the photoconductive layer 102 and the above specific non-single crystal silicon carbide film forming the surface layer 104 , are accompanied only by minor defects.

Further, since the surface layer 104 is formed of a non-single crystal silicon carbide film, the silicon atoms as a matrix, carbon atoms in an amount of 20 to 40 atomic%, hydrogen atoms in an amount of 50 to 70 atomic% and graphite structure areas in an amount of 1 % or less per unit volume, it has a desired structural relaxation and a small defect because the hydrogen atoms in the film are sufficiently bonded to carbon atoms. Therefore, no undesirable defects are found near the interface between the photoconductive layer 102 and the surface layer 104 in the electrophotographic image forming material of the invention. The material always shows excellent electrophotographic properties and is therefore well suited for use in high performance electrophotographic copying systems.

The surface layer 104 can contain a kind of halogen atoms from the group consisting of fluorine atoms (F) and chlorine atoms (Cl) in order to further reduce the defect density and, if necessary, further improve the film resistance.

The amount of these halogen atoms to be incorporated in the surface layer 104 is preferably in the range of 10 atomic ppm to 5 atomic%.

The thickness of the surface layer 104 should be determined appropriately in view of the correlation with the thickness of the photoconductive layer 102 and also with other related factors. In general, however, it is in the range of 500 Å to 10 µm.

Production of the layers

Now the process of forming the light receiving layer of the electrophotographic image forming material.

Each layer that is part of the light receiving layer of the electrophotographic image forming material of the present invention can be obtained by the microwave plasma chemical vapor deposition method (MW-PCVD method for short) using the MW-PCVD shown in Figs. 6 (A) and 6 (B) Apparatus are produced, the relevant film-forming starting material gases being used selectively.

Fig. 6 (A) is a partially broken away schematic longitudinal section of an MW-PCVD apparatus suitable for practicing the MW-PCVD method. Fig. 6 (B) is a schematic partial section of the MW-PCVD apparatus shown in Fig. 6 (A). The MW-PCVD apparatus shown in FIGS . 6 (A) and 6 (B) comprises a substantially enclosed cylindrical deposition chamber 601 with a discharge space (reaction space) 606 . The deposition chamber 601 is provided with a microwave-permeable window 602 made of alumina ceramic, a waveguide 603 for microwaves coming from a microwave energy source (not shown), a suction line 604 which is connected to a suction device via a main valve (not shown) how a diffusion pump (not shown) is connected. A plurality of rotatable cylindrical substrate holders 607 are mounted in the deposition chamber 601 , on each of which there is a cylindrical substrate 605 , so that these surround the discharge space 606 . An electrical heater is installed in all cylindrical substrate holders 607 . Reference numeral 610 denotes each of a motor for the rotation of each cylindrical substrate holder 607th Reference number 608 denotes a gas supply pipe installed in the longitudinal direction in the discharge space 606 , which comes from a gas container (not shown) via mass flow controllers (not shown). The gas supply pipe 608 has a plurality of gas discharge nozzles 608 ' through which the film-forming raw material gas is supplied to the center of the discharge space 606 . Two or more gas supply lines 608 can be installed in the discharge space 606 . In the preferred embodiment, the gas supply tube 608 is mounted in a space between two cylindrical substrate holders 607 , so that the discharge space 606 is surrounded by a plurality of cylindrical substrate holders 607 and a plurality of gas supply tubes 608 . Reference number 611 denotes a supply line with a plurality of gas discharge openings (not shown) through which a film-forming raw material gas is radially introduced into the discharge space 606 , this supply line coming from a gas container (not shown) via mass flow controller (not shown). The supply line 611 runs in the longitudinal direction near or in the middle of the discharge space 606 . The supply line 611 functions not only as a gas supply line but also as a bias electrode. Reference numeral 612 denotes a bias voltage source for applying a DC, AC or RF bias to the feed pipe 611 .

Manufacture of charge injection inhibition layer 103 (1) Production of the charge injection inhibition layer 103 with the above-mentioned specific non-single crystal silicon carbide film

The production of the charge injection inhibition layer 103 with the aforementioned specific non-single crystal silicon carbide film containing atoms of an element capable of controlling the valence electrons by the MW-PCVD method using the MW shown in FIGS . 6 (A) and 6 (B). PCVD equipment is e.g. B. performed in the following manner.

First, a cylindrical substrate 605 for electrophotography is placed on each cylindrical substrate holder 607 in the deposition chamber 601 . Then, all of the cylindrical substrate holders are rotated by the motors 610 . Then, the inside of the deposition chamber 601 is evacuated by a diffusion pump (not shown) to bring the discharge space 606 to a vacuum of 10 ^-6 Torr or less.

Then, the electric heater of each cylindrical substrate holder 607 is turned on to heat each cylindrical substrate 605 to a temperature in the range of 200 to 400 ° C, and all the cylindrical substrates are kept at this temperature.

Subsequently, a raw material gas for forming the charge injection inhibiting layer is introduced at a predetermined flow rate through the gas supply line 608 or the supply line 611 into the discharge space 606 . In a preferred embodiment, a raw material gas capable of supplying carbon atoms (hereinafter referred to as "carbon atom supplying gas") is supplied through gas supply line 608 , and a raw material capable of supplying silicon atoms (hereinafter referred to as "silicon atom supplying gas"), one for supply A raw material gas capable of hydrogen atoms (hereinafter referred to as a "hydrogen atom supplying gas") and a raw material gas capable of supplying atoms of a valence electron controlling element (hereinafter referred to as a "valence electron controlling gas") are supplied through the feed line 611 . As with the gas supplying the above-mentioned carbon atom, it is desirable that the gas be involved in the film formation as much as possible in a short time without being exposed to the plasma for a long time, for the following reason. If the decomposition of the carbon atom providing gas takes place within the plasma and carbon atoms are released therein, these carbon atoms tend to react with the supplied carbon atom providing gas and / or with carbon atoms in the deposited film and thereby a graphite structure in the resulting deposition film assume because these carbon atoms released in the plasma are very reactive.

When manufacturing a large device, such as. B. an electrophotographic Image forming material in which the layer thickness should be some ten microns, the film formation with a high deposition rate. In this The gas supplying the silicon atom must have a sufficient decomposition energy be awarded. To continue the resulting separation film not to be defective and the electrical To improve the properties of the resulting deposition film, it is necessary to use a gas supplying a hydrogen atom. For example, when this hydrogen atom-providing gas is in the form of H₂ gas is present, the hydrogen supplying gas does not carry enough to improve the electrical properties of the emerging Deposition film at and if in the reaction scheme from hydrogen radicals are formed in the hydrogen supplying gas, then wear them to improve the electrical properties of the resulting deposition film. It is also effective Exploitation of the gas controlling the valence electron necessary to bring this gas into a state that it is in the plasma absorbs enough decomposition energy.

These findings were the result of various experimental investigations by the inventors for the purpose of forming a suitable non-single crystal silicon carbide film suitable for forming the charge injection inhibiting layer 103 of the electrophotographic image forming material of the present invention.

After the selected raw material gases are introduced into the discharge space with the associated flow velocities in the above-mentioned manner, the internal pressure of the discharge space is adjusted to a predetermined vacuum of 0.1 Torr or less by regulating the main valve of the suction line 604 . After the flow rates of the raw material gases and the vacuum of the discharge space become stable, the microwave energy source is turned on to introduce microwave energy into the discharge space 606 through the waveguide 603 and the microwave transparent window 602 .

The microwave energy introduced into the discharge space 606 is at least 1.1 times the energy required to saturate the deposition rate.

The subject raw material film-forming gases, including hydrogen gas, therefore receive sufficient microwave energy and are decomposed and produce active ingredients capable of forming a deposited film on all cylindrical substrates 605 .

While the film-forming raw material gases are introduced into the discharge space 601 in the above-described operations, the electrical bias source 612 is turned on to apply a DC bias to the supply line 611 . The ions in the plasma generated in the discharge space 606 are supplied with sufficient energy so that the atoms capable of forming the deposition film on the surface of the cylindrical substrate 605 are rearranged in a desirable manner so that the above-mentioned non-single crystal silicon carbide film with excellent electrical properties forms, which is suitable as charge information inhibition layer 103 on the cylindrical substrate 605 . In this case, feed line 611 must be positive. If the feed line 611 is made negative, a DC bias effect cannot be achieved.

In the above case, high-frequency bias power can be applied instead of the DC bias power. The same effect is then achieved as when applying the bias energy mentioned. If e.g. B. RF bias power of 13.56 MHz is applied, a vacuum of about 1 × 10 ^-3 Torr significantly improves the stability of the plasma discharge.

The application of the direct current or RF electric power to the supply pipe 611 through which a gas supplying silicon atom is supplied to the discharge space 606 is an important factor in giving the silicon atom supplying gas sufficient energy for the sufficient decomposition, and so on Carbon atom provides a suitable amount of energy to transfer, so that it is not decomposed too much, but will soon be implemented.

The internal pressure of the discharge space 606 is also an important factor in forming a desired non-single crystal silicon carbide film of the invention. It is preferably 1 × 10 ^-1 torr or less, and is particularly in the range of 5 × 10 ^-4 to 1 × 10 ^-2 torr.

Likewise, the electrical bias power applied to the feed pipe is an important factor. It is preferably set to 0.2 to 1.5 times the microwave power that is applied to the discharge space 606 . In particular, it is set to 0.5 to 1.0 times the microwave power mentioned.

If the electrical bias power is less than that specified lower limit, the desired bias effect can cannot be reached. If the electrical bias power is greater than the upper limit, the resulting one Deposition film with missing parts.

It has been found experimentally that the electrical bias power applied to the supply line 611 through which the silicon atom-supplying gas is supplied to the discharge space 606 is closely related to the deposition rate, the vapor phase reaction in the plasma, and the surface reaction on the surface of each cylindrical substrate 605 , and only when the electrical bias power is used within the above range can a desired non-single crystal silicon carbide film be formed according to the present invention.

The material of the feed tube 611 is an important factor in forming a high quality deposition film because it is always exposed to the strong plasma. Therefore, the material is required to have a high melting point, hardly be sprayed, and not to react with the film-forming raw material gas.

As a material that meets all of these conditions, for example Stainless steel, Ni, Mo, Ta, Pt, etc. can be mentioned.  

To form the desired non-single crystal silicon carbide film, with which the object of the invention is achieved, suitable Raw material gases used selectively.

Specific examples of the gas supplying the silicon atom are silane gases such as SiH₄, Si₂H₆, Si₃H₈, SiF₄, Si₂F₂, etc.

Specific examples of the carbon atom-providing gas are u. a. CH₄, C₂H₆, C₃H₈, C₂H₄, C₃H₆, C₂H₂, C₆H₆, CF₄ etc. Deviating of these can be a gaseous silicon and carbon containing Material such as (CH₃) ₄Si are used.

The quantitative ratio of the above-mentioned silicon atom-providing gas to the above-mentioned carbon atom-supplying gas which are introduced into the discharge space 606 is preferably in the range from 10/5 to 100/1, in particular in the range from 10/2 to 100/5 , each based on the flow rate ratio.

It is possible to mix these gases and to introduce the resulting gas mixture into the discharge space 606 .

To form a non-single crystal silicon carbide film higher Quality must in any case be a gas mixture with a film-forming Raw material gas and hydrogen gas are used.

In order to form a valence electron-controlled non-single crystal silicon carbide film as a charge injection inhibition layer 103 in the electrophotographic image forming material of the present invention, the above-mentioned non-single crystal silicon carbide film is doped with atoms of an element belonging to group III (if the resulting film is to be p-type) during its formation. or Group V (if the resulting film should be n-type) of the Periodic Table.

As an element of group III, there can be mentioned B, Al, Ga, In and Tl. Specific examples of raw materials, the atoms deliver such an element belonging to Group III, are for example borohydrides such as B₂H₆, B₄H₁₀, B₅H₉, B₅H₁₁, B₆H₁₀, B₆H₁₂ and B₆H₄ and the other compounds AlCl₃, GaCl₃, Ga (CH₃) ₃, InCl₃, TlCl₃, etc.  

As an element of Group V, P, As, Sb, Bi, etc. can be mentioned will. Specific examples of raw materials, the atoms of such deliver elements belonging to group V are, for example Phosphorus hydrides such as PH₃, P₂H₄, etc. and the other compounds AsH₃, SbH₃, BiH₃ etc.

As described above, the charge injection inhibiting layer 103 may contain one or more kinds of atoms from the group consisting of oxygen atoms (O), nitrogen atoms (N), fluorine atoms (F) and chlorine atoms (Cl). In order to incorporate these atoms into the charge injection inhibition layer during the formation of the above-mentioned valence electron-controlled non-single crystal silicon carbide film, a suitable starting material capable of supplying these atoms is introduced into the discharge space.

O₂, NO, NO₂, N₂O etc.

As a gas supplying nitrogen atom, mention should be made of N₂, NH₃, etc.

Specific examples of the fluorine atom-providing gas are for example SiF₄, Si₂F₆, F₂, CF₄, HF etc. Specific examples the chlorine atom supplying gas are HCl, Cl₂, SiCl₄ etc.

(2) Production of the charge injection inhibition layer 103 with a single crystal free silicon-containing film different from the aforementioned single crystal silicon carbide specific film

As previously described, the charge injection inhibiting layer 103 of the electrophotographic image forming material may be formed of a single crystal free silicon-containing film selected from the group consisting of a single crystal free silicon film such as an amorphous silicon film, a non-single crystal silicon oxide film, a non-single crystal silicon nitride film and one known non-single crystal silicon carbide film, which is doped with atoms of a valence electron-controlling element.

In this case, the formation of the charge injection inhibition layer 103 can be performed as in the above case (1) using the embodiment shown in Fig. 6 (A) and 6 (B) MW-PCVD apparatus in a similar manner.

In this case, the strict film formation conditions are like not necessary in the above case (1); it can be conventional Film forming conditions selectively apply the usual MW-PCVD process for the formation of single-crystal-free silicon containing film.

As a film-forming raw material gas for the formation of a Non-single crystal silicon film is mainly SiH₄, Si₂H₆, Si₃H₈, SiF₄ or Si₂F₆ used.

If a non-single crystal silicon oxide film is formed, is used in addition to the silane gas mentioned as the main film-forming Starting material gases O₂, NO, N₂O, CO or CO₂ used.

When forming a non-single crystal silicon nitride film is used in addition to the above silane gas as the main film-forming Starting material gas N₂ or NH₃ used.

Likewise, to form a non-single crystal silicon carbide film in addition to the above silane gas as the main film-forming Starting material gas CH₄, C₂H₆, C₃H₈, C₂H₄, C₃H₆, C₂H₂ or C₆H₆ used.

In order for this single crystal free silicon containing film to be suitable for forming the charge injection inhibition layer 103 , this film is doped with atoms of a suitable valence electron control element belonging to group III for the p type or to group V of the periodic system for the n type by introducing a suitable group III or V element gas selected from the gases mentioned in the above case (1) into the discharge space 606 alone or together with a film-forming raw material gas.

In this case, the charge injection inhibition layer 103 may contain one or more atom types of the group consisting of hydrogen atoms (H) and halogen atoms (X), ie fluorine atoms (F) and chlorine atoms (Cl).

The incorporation of hydrogen atoms can be achieved if hydrogen gas (H₂) is introduced into the discharge space 606 either alone or together with the film-forming starting material gas during the film formation process.

The incorporation of halogen atoms (X) can be accomplished by adding a suitable halogen atom (X) gas from those mentioned in the above case (1) to the film forming process, either alone or together with the film forming raw material gas Discharge space 606 introduces.

Production of the photoconductive layer 102

As mentioned above, the photoconductive layer 102 in the electrophotographic image forming material of the present invention comprises the aforementioned specific non-single crystal silicon carbide film.

The photoconductive layer 102 is formed by repeating the same measures for the formation of the undoped specific non-single crystal silicon carbide film as described in detail in the above-mentioned manufacturing case (1) for the charge injection inhibiting layer 103 .

The photoconductive layer 102 in the electrophotographic image forming material according to the invention can be p-type or n-type.

In order to make the photoconductive layer p-type or n-type, the above-mentioned specific non-single crystal silicon carbide film is doped with atoms of an element of group III of the periodic system or of group V of the periodic system as well as in the formation of the charge injection inhibition layer of the p- Type or the charge injection inhibition layer of the n-type in the above-described production (1) of the charge injection inhibition layer 103 .

As with the charge injection inhibiting layer 103 , the photoconductive layer 102 may contain one or more types of atoms from the group consisting of oxygen atoms (O), nitrogen atoms (N), fluorine atoms (F) and chlorine atoms (Cl), if necessary.

The incorporation of these atoms in the photoconductive layer 102 can be carried out by repeating the same operations as in the above-described production (1) of the charge injection inhibiting layer.

Fabrication of surface layer 104

As previously described, in a preferred embodiment of the electrophotographic image forming material of the present invention, the surface layer 104 is made of a non-single crystal silicon carbide film, the silicon atoms as a matrix, carbon atoms in an amount of 20 to 40 atom%, hydrogen atoms in an amount of 50 to 70 atom% and graphite structure districts in a proportion of 1% or less per unit volume.

In this case, the surface layer 104 can be formed by repeating the measures for forming the undoped specific non-single crystal silicon carbide film as detailed in the above production (1) of the charge injection inhibiting layer 103 , with the difference that the flow rate of the carbon atom-providing gas is relatively higher is set as the gas supplying the silicon atom so that the content of the carbon atoms contained in the resulting film is in the range of 20 to 40 atomic%, the substrate temperature is set in the range of 20 to 150 ° C, and the flow rate of the hydrogen gas is controlled so that the content of the hydrogen atoms in the resulting film is in the range of 50 to 70 atomic%.

Alternatively, as mentioned above, surface layer 104 may be formed from a suitable translucent film with no substantial photoconductivity, such as a non-single crystal silicon oxide film, a non-single crystal silicon nitride film, or a non-single crystal silicon carbide film containing a relatively large amount of carbon atoms.

In this case, this translucent film for forming the surface layer 104 can be formed according to the procedures described in the above-mentioned manufacturing case (2) of the charge injection inhibiting layer.

The invention will now be described in more detail with reference to the Examples are described without limiting the scope of the invention to them Examples should be limited.

Example 1 and Comparative Example 1

The aforementioned operations for practicing the MW-PCVD method using the MW-PCVD apparatus described in Figs. 6 (A) and 6 (B) were carried out under the film formation conditions shown in Table 1, in which the character A of of the present invention are different film formation conditions and the character B is film formation conditions of the present invention. Thereby, 14 non-single crystal silicon carbide film sample groups (Sample Nos. 001 to 0014) were produced, each sample group containing 6 non-single crystal silicon carbide film samples.

In each sample group, a pair consisting of a glass plate and an Si plate plate, each measuring 2.54 cm × 5.08 cm, was placed in the respective channels on the upper part of all 6 cylindrical aluminum substrates 605 of 108 mm outside diameter, 360 mm high and 5 mm Thickness inserted into the deposition chamber 601 . A non-single crystal silicon carbide film was formed on each of these glass plates and Si plate plates. A glass plate made of Corning No. 7059 (product of Corning Glass Works, USA) was used as the glass plate.

The film composition was obtained on the samples thus obtained and determined the film structure. It was also the film quality determined.

The results obtained are summarized in Table 2. The measured values given in Table 2 are average values six samples.  

(i) The hydrogen content of the film sample was determined according to a conventional method using FTIR (Nicolet 60 SXB) on the film created on the Si wafer plate.

(ii) Determination of the IR intensity ratio of the film was carried out according to a conventional method using FTIR (Nicolet 60 SXB) on that formed on the Si disk plate Movie

(iii) The carbon content was determined on the film formed on the glass plate using XMA (product the Hitachi Seisakujo K.K.:X-650).

(iv) The determination of the content of the graphite areas in the Film was carried out as follows.

First, the Si disk plate with the one on it resulting film in a Raman laser spectrophotometer (product Japan Spectroscopic Co., Ltd.:NR-1100) to measure the Raman spectrum.

Then, the proportion (%) of the graphite structure areas per unit volume in the film was obtained by making the peak area between 480 cm ^-1 and 520 cm ^-1 related to the TO mode of the silicon atom as a control value equal to 100 % was set and the total area of all peaks appearing between 1450 cm ^-1 and 1710 cm ^-1 , which related to graphite, was compared with the mentioned control value.

(v) When evaluating the film quality of the resulting film became the final state of the film formed on the glass plate conventional photothermal deflection spectroscopy measured (see Semiconductors and Semimetals, Vol. 21, p. 83 (1984), Academic Press, Inc.).

The measured extinction coefficient can be related to express the Urbach end by the following equation:

where α is the extinction coefficient, α ₀ is a constant, H _{ν is} the radiated energy and Ec is the characteristic energy. The smaller the broadening of the final state, the smaller the characteristic energy (Ec) . That is, one can say that the smaller the characteristic energy Ec , the better the film quality.

The sample identification numbers in Table 2 correspond those in Table 1.

From the results in Table 2 it can be seen that the resulting films of Sample Nos. 011, 012, 013 and 014 dem specific non-single crystal silicon carbide film according to the invention corresponding. H. a non-single crystal silicon carbide film, of silicon atoms as a matrix, carbon atoms in an amount of 5 to 15 atomic%, hydrogen atoms in an amount of 1 to 10 atomic% and graphite structure districts in a proportion of 1% or contains less per unit volume and in the infrared absorption spectrum an intensity ratio between the C-H bond stretching mode and the Si-H bond stretching mode from 0.01 to Has 0.05.

It was also found that all four films above were one have characteristic energy less than that of all other comparison films and this exceeds the film quality.

Comparative Example 2

In this comparative example, a high-frequency glow discharge decomposition method (13.56 MHz) was used by using the film forming apparatus shown in Fig. 7, which is suitable for practicing this method. In this comparative example, a film was formed on a Corning No. 7059 glass plate and also on a 2.54 cm × 5.08 cm Si plate plate. These plates were placed in the relevant channels on the upper part of a cylindrical aluminum sample holder 703 ' of 108 mm outer diameter, 360 mm length and 5 mm thickness, which in the deposition chamber 701 under the film formation conditions for sample No. 015 given in Table 3 on a cylindrical Substrate holder was placed.

Film formation was carried out in the following manner carried out.  

First, the cylindrical aluminum sample holder 703 'disposed thereon with the glass plate and silicon wafer plate was placed on the substrate holder 703rd Then the suction valve 705 was opened and the deposition space of the chamber 701 was evacuated by the operation of the vacuum pump (not shown).

After the display of the vacuum gauge 704 was about 1 × 10 ^-3 Torr, SiH₄ gas and H₂ gas were connected through several gas discharge openings (not shown) of the gas supply pipe 711 , which was connected via a line 709 with a supply valve 707 to gas containers (not shown) was introduced at flow rates of 1000 and 5000 standard cm "/ min in the deposition chamber of the deposition chamber 701. FIG. at the same time C₂H₂-gas (not shown) through a plurality of gas discharge openings in the feed tube 702 to a line 710 with a supply valve 708 a gas tank (not shown) was connected into the deposition space of the deposition chamber 701 at a flow rate of 100 standard / cm³ / min.

The temperature of the cylindrical aluminum sample holder 703 was adjusted by an electric heater 706 .

After the initial measures were completed, a high frequency source (not shown) was turned on to introduce RF power into the deposition space of the deposition chamber 701 . In this way, a film was deposited on the glass plate and the Si plate.

The films thus obtained were processed in the same manner as evaluated in Example 1.

The results are shown in Table 4. From table 4 it can be seen that when a non-single crystal silicon carbide film is formed according to the HF glow discharge decomposition method used in the formed film increases the amount of hydrogen atoms and the proportion of graphite areas formed in the resulting film gets big.  

Example 2 and Comparative Example 2

In Example 2, a plurality of electrophotographic image forming materials of the structure shown in Fig. 1 (A) were produced by the same film formation methods as in Example 1, except that neither the glass plate nor the Si plate plate, but a cylindrical aluminum substrate 101 of 108 mm outer diameter, 360 mm Length and 5 mm thickness was used and the film formation conditions shown in Table 1 used for Sample Nos. 011 to 014 were used.

In Comparative Example 3, a plurality of electrophotographic image forming materials having the structure shown in Fig. 1 (A) were produced by the same film-forming measures as in Comparative Example 1, except that neither the glass plate nor the Si plate plate, but a cylindrical aluminum substrate 101 of 108 mm outer diameter, 6 70124 00070 552 001000280000000200012000285917001300040 0002003927353 00004 700050 mm long and 5 mm thick under the film formation conditions of sample No. 001 to 010 given in Table 1 and the film formation conditions for sample No. 115 given in Table 3.

The thickness of the photoconductive layer 102 was 25 μm in each case. The electrophotographic properties of each of the electrophotographic film forming material samples thus obtained were determined on a conventional high-speed electrophotographic copying machine (product of Canon KK: NP 8570). For this determination, the aforementioned electrophotographic copying machine was modified so that charge retention, dark decay, photosensitivity and ghosting could be assessed and an operating speed of 90 copies / minute (size A-4) could be achieved.

Each of the resulting samples was modified into this high-performance electrophotographic copying machine used, about charge retention, dark decay, photosensitivity and determine the appearance of the ghosting, wherein Light of a wavelength of 700 nm at 20 erg in the pre-exposure  was irradiated.

As a result of testing the surface electrical potential on the electrophotographic image forming material of the invention, a typical curve of this potential over time was obtained in the electrophotographic image forming method, as shown in Fig. 8 (A).

It can be understood from the curve shown in Fig. 8 (A) that the surface electric potential of the electrophotographic image forming material changes with corona charging and exposure. That is, the electrical surface potential increases from the position "0" to the position "P ₁", where it assumes the value Vs with corona charging. The electrophotographic image forming material then moves to the exposure zone (P ₂). During this period, the electrical surface potential due to dark decay takes on the value Vd . In the exposure zone (P ₂) said material is image exposed, and then the electrical surface potential decreases to the value Ve at the point "P ₃".

In this context the charge retention was determined by Vd in the corona current. The dark decay was determined by a quantity obtained by the equation: Vs-Vd , in which Vd was kept constant. Photosensitivity was determined by the amount of exposure light (wavelength 500 nm) required to reach a surface electric potential Ve corresponding to 10% of Vd , making Vd constant.

The appearance of ghosting was in the following Determined way.

Fig. 8 (B) shows a typical graphical representation of the changes in the surface electric potential obtained when the electrophotographic image forming material of the present invention is subjected to the corona charge in a step function. To explain the graphical representation of Fig. 8 (B), it should be said that in the electrophotographic image forming method, the electrophotographic image forming material is temporarily rotated under the loader, and consequently said material repeatedly receives charges. In the embodiment shown in Fig. 8 (B) representation of a surface electric potential V _g is ₁ in the first loading and another surface electric potential V _{g 2} shown in the second load. The occurrence of ghosting was determined by a size obtained from the equation V _{g 2} - V _{g 1} .

The results thus obtained are in total in Table 5 given. All sizes shown are relative sizes. From Table 5 it can be seen that the charge retention is all the more gets better the smaller the size. The dark decay is the smaller the value, the better the appearance of Phantom images and optical attenuation are all the better, ever is smaller the value.

As a result, it has been confirmed that all of the present invention electrophotographic imaging material samples, d. H. the Samples Nos. 111, 112, 113 and 114 the other comparative samples of the electrophotographic image forming material in all outperform the above assessment points and for use in an electrophotographic high-performance copier system in particular are suitable.

Example 3

Sample No. 111 obtained in Example 2 became positive Corona charge and subjected to a negative corona charge. In any case, for the electrical surface potential measured the optical attenuation, the light wavelength was changed.

The results obtained were summarized in Fig. 9 (negative loading) and in Fig. 10 (positive loading).

From the in Fig. 9 and Fig. 10 apparent results it is understood that the electrophotographic image-forming material of Sample Nos. 111 shows in the negative corona charging or the positive corona charging desirable properties.

Example 4 and Comparative Example 4

The above-mentioned operations for performing the MW-PCVD method using the MW-PCVD apparatus (2.45 GHz) shown in Figs. 6 (A) and 6 (B) were carried out under the film forming conditions of Table 6, in wherein the character A denotes the film formation conditions deviating from the present invention and the symbol B denotes the film formation conditions according to the present invention. In this way, 14 non-single crystal silicon carbide film sample groups (Sample Nos. 201 to 214) were prepared, each sample group containing 6 non-single crystal silicon carbide film samples.

In each sample group, a pair consisting of a glass plate and an Si plate plate, each measuring 2.54 cm × 5.08 cm, were placed in the respective channels on the upper part of all 6 cylindrical aluminum substrates 605 of 108 mm outside diameter, 360 mm high and 5 mm Thickness inserted into the deposition chamber 601 . A non-single crystal silicon carbide film was formed on each of these glass plates and Si plate plates. A plate made of glass Cornin No. 7059 was used as the glass plate.

The film composition, the film structure and film quality in the same way as determined in Example 1.

The results as a whole are in Table 7 given. The measured values given in Table 7 are mean values from 6 samples.

The identification numbers of the samples in Table 7 correspond those in Table 6.

From the results in Table 7 it can be seen that the resulting films of Sample Nos. 211, 212, 213 and 214 the specific non-single crystal silicon carbide film according to the invention corresponding. H. a non-single crystal silicon carbide film, of silicon atoms as a matrix, carbon atoms in an amount of 5 to 15 atomic%, hydrogen atoms in an amount of 1 to 10 atomic% and graphite structure districts in a proportion of 1% or contains less per unit volume and in the infrared absorption spectrum  an intensity ratio between the C-H bond stretching mode and the Si-H bond stretching mode from 0.01 to Has 0.05. It was also found that all four films above have a characteristic energy less than that of all other comparison films and this in film quality surpasses.

Comparative Example 5

In this comparative example, a high-frequency glow discharge decomposition method (13.56 MHz) was used by using the film forming apparatus shown in Fig. 7, which is suitable for practicing this method. In this comparative example, a film was formed on a Corning No. 7059 glass plate and also on a 2.54 cm × 5.08 cm Si plate plate. These plates were placed in the relevant channels on the upper part of a cylindrical aluminum sample holder 703 ' of 108 mm outer diameter, 360 mm length and 5 mm thickness, which in the deposition chamber 701 under the film formation conditions for sample No. 215 given in Table 8 on a cylindrical Substrate holder was placed.

Film formation was carried out in the following manner carried out.

First, the cylindrical aluminum sample holder with the glass plate and Si disk plate arranged thereon was placed on the substrate holder 703 . Then the suction valve 705 was opened and the deposition space of the chamber 701 was evacuated by the operation of the vacuum pump (not shown).

After the display of the vacuum gauge 704 was 1 × 10 ^-3 Torr, SiH₄ gas and H₂ gas were introduced through the feed valve 707 and the feed pipe 701 into the deposition space of the deposition chamber 701 . At the same time, C₂H₂ gas was introduced into the deposition space through the feed valve 708 and the feed line 702 .

The temperature of the cylindrical aluminum sample holder 703 ' was set by an electric heater 706 .

After the initial measures were completed, a radio frequency source (not shown) was turned on to introduce RF power into the deposition space of the deposition chamber 701 . In this way, a film was deposited on the glass plate and the Si plate.

The films thus obtained were processed in the same manner as evaluated in Example 1.

The results are shown in Table 9. From table 9 it can be seen that when a non-single crystal silicon carbide film is formed according to the HF glow discharge decomposition method used in the formed film increases the amount of hydrogen atoms and the proportion of graphite areas formed in the resulting film gets big.

Example 5 and Comparative Example 6

In Example 5, under the film formation conditions shown in Table 10, several electrophotographic image forming material samples were produced having the structure shown in Fig. 1 (B), which was a substrate 101 having a cylindrical aluminum substrate 108 mm in outside diameter, 360 mm in length and 5 mm in thickness, and a light receiving layer with a 3 μm thick charge injection inhibition layer 103 made of a specifically doped non-single crystal silicon carbide film and a 25 μm thick photoconductive layer 102 made of a specific undoped non-single crystal silicon carbide film.

Similarly, in Comparative Example 6, a plurality of electrophotographic image forming materials having the structure shown in Fig. 1 (B) were produced under the film formation conditions shown in Table 11.

All electrophotographic imaging materials so produced were in the same manner as in Example 2 checked.

The test results obtained are shown in Table 12. All stated values are relative values. From table 12 is understandable that the charge retention is the better, ever  the smaller the value, the darker the decay, the better is smaller the value, and the ghosting and the optical attenuation the better the smaller the value.

As a result, it was confirmed that all electrophotographic Imaging material samples of the invention, namely the Sample Nos. 311, 312, 313 and 314, the other comparative samples of the electrophotographic image forming material in all surpass the above assessment points and especially for electro high performance photographic copier systems are suitable.

Example 6 and Comparative Example 7

In Example 6, under the film formation conditions shown in Table 13, a plurality of electrophotographic image forming material samples having the structure shown in Fig. 1 (B) were prepared, which a substrate 101 with a cylindrical aluminum substrate of 108 mm in outer diameter, 360 mm in length and 5 mm in thickness as well a light receiving layer with a 3 µm thick charge injection inhibition layer 103 made of a specifically doped non-single crystal silicon carbide film and a 25 µm thick photoconductive layer 102 made of a specific undoped non-single crystal silicon carbide film.

Similarly, in Comparative Example 7, a plurality of electrophotographic image forming materials having the structure shown in Fig. 1 (B) were produced under the film forming conditions shown in Table 14.

All electrophotographic image form thus produced Materials were made in the same manner as in Example 2 checked.

The test results obtained are shown in Table 15. All stated values are relative values. From table 15 is understandable that the charge retention is the better, ever the smaller the value, the darker the decay, the better is smaller the value, and the ghosting and the optical attenuation the better the smaller the value.

As a result, it was confirmed that all electrophotographic  Imaging material samples of the invention, namely the Samples Nos. 411, 412, 413 and 414, the remaining comparative samples of the electrophotographic image forming material in all surpass the above assessment points and especially for electro high performance photographic copier systems are suitable.

Example 7 and Comparative Example 8

In Example 7, several electrophotographic image forming material samples having the structure shown in Fig. 1 (B) were prepared under the film formation conditions shown in Table 16, which a substrate 101 with a cylindrical aluminum substrate of 108 mm outer diameter, 360 mm long and 5 mm thick as well a light receiving layer with a 3 cm thick charge injection inhibition layer 103 made of a specifically doped non-single crystal silicon carbide film and a 25 µm thick photoconductive layer 102 made of a specific undoped non-single crystal silicon carbide film.

Similarly, in Comparative Example 8, several electrophotographic image forming materials having the structure shown in Fig. 1 (B) were produced under the film forming conditions shown in Table 17.

All electrophotographic image formation thus produced materials were processed in the same manner as in Example 2 checks.

The results thus obtained are overall in Table 18 specified. All values are relative values. From the information in Table 18 shows that cargo retention is all the more so the smaller the value, the darker the better the smaller the value and the phantom image phenomenon is better and the smaller the optical attenuation, the better the value is.

As a result, it was confirmed that all electrophotographic Imaging material samples of the invention, namely the Samples Nos. 511, 512, 513 and 514, the remaining comparative samples of the electrophotographic image forming material in all  surpass the above assessment points and especially for electro high performance photographic copier systems are suitable.

Example 8 and Comparative Example 9

Under the film formation conditions shown in Table 19, several electrophotographic image forming material samples were prepared of the structure shown in Fig. 1 (B), which was a cylindrical aluminum substrate 101 of 108 mm in outer diameter, 360 mm in length and 5 mm in thickness, and a light receiving layer made of a 3 µm thick charge injection inhibiting layer 103 comprised of a doped non-single crystal silicon carbide film and a 25 μm thick photoconductive layer 102 made of a doped non-single crystal silicon carbide film.

All electrophotographic image formation thus produced materials were evaluated in the same manner as in Example 2.

The results thus obtained are in total in Table 20 given. All stated values are relative values. From Table 20 it can be understood that the charge retention the smaller the value, the better the dark decay the smaller the value, and the ghosting phenomenon is better and the lower the optical attenuation, the better Is worth.

As a result, it was confirmed that all electrophotographic Imaging material samples of the invention, namely the Samples Nos. 611, 612, 613 and 614, the other comparative samples from electrophotographic image forming material in all of the above Exceed evaluation points and especially for electrophoto graphic high-performance copier systems are suitable.

Example 9 and Comparative Example 10

The above-mentioned operations for performing the MW-PCVD method using the MW-PCVD apparatus (2.54 GHz) shown in Figs. 6 (A) and 6 (B) were carried out under the film forming conditions of Table 21 in which the character A denotes the film formation conditions deviating from the present invention and the character B denotes the film formation conditions according to the present invention. In this way, 14 non-single crystal silicon carbide film sample groups (Sample Nos. 701 to 714) were prepared, each sample group containing 6 non-single crystal silicon carbide film sample films.

In each sample group, a few plates, consisting of a glass plate and an Si plate plate, each in the size 2.54 cm × 5.08 cm, were placed in the respective channels on the upper part of all 6 cylindrical aluminum substrates 605 of 108 mm outside diameter, 360 mm height and 5 mm thick inserted into the deposition chamber. A non-single crystal silicon carbide film was formed on each of these glass plates and Si plate plates. A plate made of Corning glass No. 7059 was used as the glass plate.

The film composition, the film structure and film quality in the same way as determined in Example 1.

The results as a whole are in Table 22 given. The measured values given in Table 22 are Average values from 6 samples.

The identification numbers of the samples in Table 22 speak to those in Table 21.

From the results in Table 22 it can be seen that the resulting films of samples 711, 712, 713 and 714 the specific Non-single crystal silicon carbide film according to the invention corresponding. H. a non-single crystal silicon carbide film which Silicon atoms as a matrix, carbon atoms in an amount of 5 to 15 atomic%, hydrogen atoms in an amount of 1 to 10 Atomic% and graphite structure districts in a share of 1% or contains less per unit volume and in the infrared absorber tion spectrum an intensity ratio between the C-H bond stretching mode and the Si-H bond stretching mode from 0.01 to Has 0.05. It was also found that all four films above have a characteristic energy that is less than that of all other comparison films and this in the film quality about meets.  

Comparative Example 11

In this comparative example, a high-frequency glow discharge decomposition method (13.56 MHz) was used by using the film forming apparatus shown in Fig. 7, which is suitable for practicing this method. In this comparative example, a film was formed on a Corning No. 7059 glass plate and also on a 2.54 cm × 5.08 cm Si plate plate. These plates were placed in the relevant channels on the upper part of a cylindrical aluminum sample holder 703 ' of 108 mm outer diameter, 360 mm length and 5 mm thickness, which in the deposition chamber 710 under the film formation conditions for sample No. 715 given in Table 23 on a cylindrical Substrate holder was set.

The film was shown in the following Wise.

First, the cylindrical aluminum sample holder with the glass plate and Si disk plate arranged thereon was placed on the substrate holder 703 . Then the suction valve 705 was opened, and the deposition chamber of the deposition chamber was evacuated by the operation of the vacuum pump (not shown).

After the display of the vacuum gauge 704 was 1 × 10 ^-3 Torr, SiH₄ gas and H₂ gas were introduced through the feed valve 707 and the feed pipe 711 into the deposition space from the deposition chamber 701 . At the same time, C₂H₂ gas was introduced into the deposition space through the feed valve 708 and the feed line 702 .

The temperature of the cylindrical aluminum sample holder 703 ' was set by an electric heater 706 .

After the initial measures were completed, a radio frequency source (not shown) was turned on to introduce RF power into the deposition space of the deposition chamber 701 . In this way, a film was deposited on the glass plate and the Si disk plate.

The films thus obtained were processed in the same manner as  evaluated in Example 1.

The results are shown in Table 24. From table 24 It can be seen that when a non-single crystal Si silicon carbide film by the HF glow discharge decomposition method the amount of hydrogen atoms included in the film formed increases and the proportion of those formed in the resulting film Graphite districts becomes large.

Example 10 and Comparative Example 12

The above-mentioned operations for performing the MW-PCVD method using the MW-PCVD apparatus shown in Figs. 6 (A) and 6 (B) were carried out under the film forming conditions of Table 25, in which the character A is the film formation conditions other than the present invention and the character B mean the film formation conditions according to the present invention. In this way, 7 non-single crystal silicon carbide film sample groups (Sample Nos. 801 to 807) were prepared, each sample group containing 6 non-single crystal silicon carbide film samples.

In each sample group, a pair of plates consisting of a glass plate and an Si plate plate, each 2.54 cm × 5.08 cm in size, were inserted into the channels on the upper part of all 6 cylindrical aluminum substrates 605 with an outside diameter of 108 mm, a height of 360 mm and a thickness of 5 mm inserted into the deposition chamber 601 . A non-single crystal silicon carbide film was formed on each of these glass plates and Si plate plates. A plate made of Corning glass No. 7059 was used as the glass plate.

The film composition, the film structure and film quality in the same way as in Example 1 determined.

The results as a whole are in Table 26 indicated. The measured values given in Tab. 26 are Average values from six samples.

The identification numbers of the samples in Table 26 speak to those in Table 25.  

It can be seen from the results given in Table 26 that all films of sample no. 805, 806 and 807 are excellent in quality and surpass the other resulting films not only in the characteristic energy (Ec) but also in other properties and are therefore suitable as a surface layer 104 in the electrophotographic imaging material according to the invention. It has been confirmed that each non-single crystal silicon carbide film is one with silicon atoms as a matrix, carbon atoms in an amount of 20 to 40 atomic%, hydrogen atoms in an amount of 50 to 70 atomic% and graphite structure areas in an amount of 1% or less per unit volume.

Example 11 and Comparative Example 13

In Example 11 and Comparative Example 13, a plurality of electrophotographic image forming materials were produced having the structure shown in Fig. 1 (C), which was a cylindrical aluminum substrate 101 108 mm in outer diameter, 360 mm in length and 5 mm in thickness, and a light receiving layer with a 25 µm thick photoconductive layer 102 and a 0.5 micron thick surface layer 104 comprises.

In Example 11, the majority of the electrophoto graphic image forming materials among those in Table 27 specified film formation conditions.

In Comparative Example 13, the majority of the electro photographic image forming materials among those in Table 28 specified film formation conditions.

All electrophotographic image form thus produced Materials were made in the same manner as in Example 2 rated.

The results thus obtained are overall in Table 29 specified. All values given there are relative values. Out Table 29 understands that cargo retention is all the more so the smaller the value, the darker the better the smaller the value, and the ghosting phenomenon is better  and the lower the optical attenuation, the better Is worth.

As a result, it was confirmed that all electrophotographic Imaging material samples of the invention, namely the Sample Nos. 911, 912, 913 and 914, the other comparative samples of the electrophotographic image forming material in all exceed the above evaluation criteria and especially for elec trophotographic high-performance copying systems are suitable.

The appearance of the drop in electrical surfaces initial potential was used in all for comparison electrophotographic image forming materials (sample no. 901-910 and 915) were observed, however the appearance was observed none of the electrophotographic belonging to the invention Imaging materials (Sample No. 911-914) observed.

Example 12 and Comparative Example 14

Under the film formation conditions shown in Tables 30 and 31, a plurality of electrophotographic image forming materials of the structure shown in Fig. 1 (D) were prepared, which were made of a cylindrical aluminum substrate 108 mm in outer diameter, 360 mm in length and 5 mm in thickness, and a light receiving layer a 3 μm thick charge injection inhibition layer 103 (first layer), a 25 μm thick photoconductive layer 102 (second layer) and a 0.5 μm thick surface layer 104 (third layer).

All electrophotographic image form thus produced Materials were made in the same manner as in Example 2 rated.

The results thus obtained are in total in Table 32 given. All stated values are relative values. From Table 32 it can be seen that the charge retention the smaller the value, the better the dark decay the smaller the value, and the ghosting phenomenon is better and the lower the optical attenuation, the better Is worth.  

As a result, it has been confirmed that all electrophotographic Imaging material samples of the invention, namely the Samples 1011, 1012, 1013 and 1014, the other comparison samples of the electrophotographic image forming material in all exceed the above assessment points and especially for elec trophotographic high-performance copying systems are suitable.

The appearance of the drop in electrical surfaces initial potential was used in all for comparison electrophotographic image forming materials (sample no. 1001-1010 and 1015) were observed, however the phenomenon was observed none of the electrophotographic ones belonging to the invention Imaging materials (Sample No. 1011-1014) observed.

Example 13 and Comparative Example 15

Under the film formation conditions shown in Table 33, a plurality of electrophotographic image forming materials of the structure shown in Fig. 1 (D) were prepared, which were a cylindrical aluminum substrate 108 mm in outer diameter, 360 mm in length and 5 mm in thickness, and a light receiving layer made of a 3 µm thick charge injection inhibiting layer 103 (first layer), a 25 μm thick photoconductive layer 102 (second layer) and a 0.5 μm thick surface layer 104 (third layer).

All electrophotographic image form thus produced Materials were made in the same manner as in Example 2 rated.

The results obtained are in total in Table 24 given. All stated values are relative values. From Table 34 it can be seen that the charge retention the smaller the value, the better the dark decay the smaller the value, and the ghosting phenomenon is better and the smaller the optical attenuation, the better Is worth.

As a result, it was confirmed that all electrophotographi image forming material samples of the invention, namely the  Samples Nos. 1111, 1112, and 1114, the remaining control samples of the electrophotographic image forming material in all exceed the above assessment points and especially for elec trophotographic high-performance copying systems are suitable.

The appearance of the drop in electrical surfaces initial potential was used in all for comparison electrophotographic image forming materials (sample no. 1101-1110 and 1115) were observed, however the phenomenon was observed none of the electrophotographic ones belonging to the invention Image formation materials (Sample No. 1111-1114) observed.

Example 14 and Comparative Example 16

Under the film formation conditions shown in Table 35, several electrophotographic image forming materials of the structure shown in Fig. 1 (D) were prepared, which were a cylindrical aluminum substrate 108 mm in outer diameter, 360 mm in length and 5 mm in thickness, and a light receiving layer made of a 3 µm thick charge injection inhibiting layer 103 (first layer), a 25 μm thick photoconductive layer 102 (second layer) and a 0.5 μm thick surface layer 104 (third layer).

All electrophotographic image form thus produced Materials were made in the same manner as in Example 2 rated.

The results thus obtained are in total in Table 36 given. All stated values are relative values. From table 36 it can be seen that the charge retention the smaller the value, the better the dark decay the better the smaller the value, and the more ghosting appearance and the optical attenuation the better, the smaller the value is.

As a result, it was confirmed that all electrophotographic Imaging material samples of the invention, namely the Samples 1211, 1212, 1213 and 1214, the remaining comparative samples of the electrophotographic image forming material in all exceed the above assessment points and especially for elec  trophotographic high-performance copying systems are suitable.

The appearance of the drop in electrical surfaces initial potential was used in all for comparison electrophotographic image forming materials (sample no. 1201-1210 and 1215) were observed, however the phenomenon was observed none of the electrophotographic ones belonging to the invention Imaging materials (Sample No. 1211-1214) observed.

Example 15 and Comparative Example 17

Under the film formation conditions shown in Table 37, several electrophotographic image forming materials of the structure shown in Fig. 1 (D) were prepared, which were a cylindrical aluminum substrate 108 mm in outer diameter, 360 mm in length and 5 mm in thickness, and a light receiving layer made of a 3 µm thick charge injection inhibiting layer 103 (first layer), a 25 μm thick photoconductive layer 102 (second layer) and a 0.5 μm thick surface layer 104 (third layer).

All electrophotographic image form thus produced Materials were made in the same manner as in Example 2 rated.

The results obtained are in total in Table 38 given. All stated values are relative values. From Table 38 it can be seen that the charge retention the smaller the value, the better the dark decay the smaller the value, the better the ghosting appearance and the optical attenuation are the better, the smaller the value is.

As a result, it was confirmed that all electrophotographi image forming material samples of the invention, namely the Samples 1305, 1306 and 1307, the other comparative samples from electrophotographic image forming material in all of the above Exceed evaluation points and especially for electro high performance photographic copier systems are suitable.  

The appearance of the drop in electrical surfaces initial potential was used in all for comparison electrophotographic image forming materials (sample no. 1301-1304) was observed, but the phenomenon was not observed in any the electrophotographic image form belonging to the invention materials (Sample No. 1305-1307) observed.

Example 16 and Comparative Example 18

Under the film formation conditions shown in Table 39, a plurality of electrophotographic image forming materials of the structure shown in Fig. 1 (D) were prepared, which were a cylindrical aluminum substrate 108 mm in outer diameter, 360 mm in length and 5 mm in thickness, and a light receiving layer made of a 3 µm thick charge injection inhibiting layer 103 ( first layer), a 25 μm thick photoconductive layer 102 (second layer) and a 0.5 μm thick surface layer 104 (third layer).

All electrophotographic image form thus produced Materials were made in the same manner as in Example 2 rated.

The results obtained are in total in Table 40 given. All stated values are relative values. From Table 40 it can be seen that the charge retention the smaller the value, the better the dark decay the smaller the value, the better the phantom image appearance and the optical attenuation are the better, ever is smaller the value.

As a result, it was confirmed that all electrophotographi image forming material samples of the invention, namely the Samples 1405, 1406 and 1407, the remaining comparative samples of the electrophotographic image forming material in all exceed the above assessment points and especially for elec trophotographic high-performance copying systems are suitable.

The appearance of the drop in electrical surfaces initial potential was used in all for comparison  electrophotographic image forming materials (sample no. 1401-1404) was observed, but the phenomenon was not observed in any the electrophotographic image form belonging to the invention material (Sample No. 1405-1407) observed.  

Table 1

Table 2

Table 3

Table 4

Table 5

Table 6

Table 7

Table 8

Table 9

Table 10

Table 11

Table 12

Table 13

Table 14

Table 15

Table 16

Table 17

Table 18

Table 19

Table 20

Table 21

Table 22

Table 23

Table 24

Table 25

Table 26

Table 27

Table 28

Table 29

Table 30

Table 31

Table 32

Table 33

Table 34

Table 35

Table 36

Table 37

Table 38

Table 39

Table 40

Claims (9)

1. Electrophotographic image forming material with a substrate for electrophotography and a light receiving layer arranged on the substrate, characterized in that the light sensitivity comprises a photoconductive layer ( 102 ) made of a non-single-crystal silicon carbide film, the silicon atoms as a matrix, carbon atoms in an amount of 5 to 15 Atomic%, hydrogen atoms in an amount of 1 to 10 atomic ‰ and graphite structure regions in a proportion of 1% or less per unit volume and in the infrared absorption spectrum an intensity ratio between the CH bond stretching mode and the Si-H bond stretching mode from 0.01 to 0.05. 2. Electrophotographic image forming material according to claim 1, characterized in that the light receiving layer further comprises a charge injection inhibition layer ( 103 ) arranged between the substrate ( 101 ) and the photoconductive layer ( 102 ). 3. Electrophotographic image forming material according to claim 3, characterized in that the charge injection inhibition layer ( 103 ) is formed from a doped, non-single-crystal, silicon-containing film from the group consisting of a doped non-single-crystal, hydrogenated silicon film, a doped, non-single-crystal silicon oxide film, one doped non-single crystal silicon nitride film and a doped non-single crystal silicon carbide film. 4. Electrophotographic image forming material according to claim 2 or 3, characterized in that the charge injection inhibition layer ( 103 ) consists of a doped non-single crystal silicon carbide film, the silicon atoms as a matrix, 5 to 15 atom% carbon atoms, 1 to 10 atom% hydrogen atoms and contains graphite structure areas in a proportion of 1% or less per unit volume and in the Infraro absorption spectrum has an intensity ratio between the CH bond stretching mode and the Si-H bond stretching mode of 0.01 to 0.05. 5. An electrophotographic image forming material according to claim 4, characterized in that the doped non-single crystal silicon carbide film atoms of a group III or / and group V element of the periodic table. 6. Electrophotographic image forming material according to one of claims 1 to 5, characterized in that the light receiving layer further comprises a surface layer ( 104 ) arranged on the photoconductive layer ( 102 ). 7. Electrophotographic image forming material according to claim 6, characterized in that the surface layer ( 104 ) consists of a non-single crystal silicon carbide film, the silicon atoms as a matrix, 20 to 40 atom% carbon atoms, 50 to 70 atom% hydrogen atoms and graphite structure areas in contains 1% or less per unit volume. 8. Electrophotographic image forming material after one of claims 1 to 7, characterized in that the non- crystal silicon carbide film atoms of an element from the group ent holds from elements of group III and elements of group V of the periodic system. 9. Electrophotographic image forming process, characterized in that

• a) applying an electric field to the electrophotographic image forming material according to any one of claims 1 to 8 and
• b) applies electromagnetic wave (s) to said electrophotographic image forming material and thereby forms an electrostatic image.