JPH02272573A - Photosensitive body - Google Patents

Abstract

PURPOSE:To decrease the change in the electrostatic potential at the time of repetitive use and to decrease dark attenuation and residual potential as well as to improve photosensitivity by incorporating group III or V elements of the periodic table into a charge generating layer and providing an intermediate layer consisting of amorphous hydrogenated and/or halogenated silicon which does not contain these elements between a charge transfer layer and the charge generating layer. CONSTITUTION:The charge generating layer 5 of the photosensitive body having the charge transfer layer consisting of the amorphous hydrogenated and/or halogenated silicon oxide and the charge generating layer consisting of the amorphous hydrogenated and/or halogenated silicon contains the group III or V elements of the periodic table. The intermediate layer 4 consisting of the amorphous hydrogenated and/or halogenated silicon which does not contain these elements is provided between the charge transfer layer 2 and the charge generating layer 5. The energy gap existing between the charge transfer layer 2 and the charge generating layer 5 is apparently drastically decreased by the non-doped intermediate layer 4. The change in the electrostatic potential at the time of the repetitive use is decreased and the dark attenuation and residual potential are decreased. In addition, the photosensitivity is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a photoreceptor, such as an electrophotographic photoreceptor.

Conventional technology Conventionally, as an electrophotographic photoreceptor, Se or Se has As, T
Photoreceptors doped with e.g., Sb, etc., and photoreceptors in which ZnO or CdS is dispersed in a resin binder are known. However, these photoreceptors have poor environmental pollution, thermal stability,
There are problems with mechanical strength.

On the other hand, electrophotographic photoreceptors using amorphous silicon (hereinafter referred to as a-3i) as a matrix have been proposed in recent years. a-3t has a so-called dangling bond in which the bond of 5i-3t is broken, and many localized levels exist within the energy gap due to this defect. For this reason, hopping conduction of thermally excited carriers occurs, resulting in a small dark resistance, and photoexcited carriers are trapped in localized levels, resulting in poor photoconductivity. Therefore, the dangling bonds are filled by compensating the defects with hydrogen atoms (H) and bonding H to Si.

Such amorphous hydrogenated silicon (hereinafter referred to as a-3
It is called t knee H. ) has a resistivity of 108 to 10 in the dark.
"Ω-1, which is about 1 when compared to amorphous Se.
It's even lower than 1/10,000. Therefore, a photoreceptor made of a single layer of a-3t:H has problems in that the dark decay rate of the surface potential is high and the initial charging potential is low. However, on the other hand, when irradiated with light in the visible and infrared regions, the resistivity is greatly reduced, so it has extremely excellent properties as a photosensitive layer of a photoreceptor.

In addition, photoreceptors with a-3i:H surfaces are susceptible to surface chemical stability, such as the effects of long-term exposure to the atmosphere and moisture, and the effects of chemical species generated by corona discharge. , has not been sufficiently investigated so far. For example 1
It is known that if the device is left for more than a month, it will be affected by moisture and its receptive potential will drop significantly. On the other hand, regarding amorphous silicon carbide (hereinafter referred to as a-3iC:H), its manufacturing method and existence are 'Ph11. Mag, Vol1
．． 35" (197B), etc., and its characteristics include high heat resistance and surface hardness, and a high dark resistivity (10" to 10'3 Ω-1) compared to a-3t:H. The optical energy gap is 1 depending on the amount of carbon.
．． It is known that it varies over a range of 6 to 2.8 eV.

Electrophotographic photoreceptors in which such a-3iC:H and a-3t:H are combined are disclosed in, for example, JP-A-58-219559, JP-A-5B-219560, JP-A-59-212840, JP-A-59-212842, etc. It is stated in the official gazette.

However, the conventional photoreceptor using a-3iC:)l has the following drawbacks. That is, since the optical energy gap of, for example, an a-3iCsH layer as a charge transport layer is considerably larger than that of a photoconductive layer (for example, an a-3i:H layer), a considerably large band gap exists between both layers. For this reason, carriers generated within the photoconductive layer during light irradiation cannot sufficiently overcome the band gap, resulting in insufficient photosensitivity.

In particular, it has been found that when the bandgap is 0.3 eV or more, the photosensitivity is considerably reduced.

Therefore, the present applicant has filed Japanese Patent Application No. 57-101084, Japanese Patent Application No. 60-123649, and Japanese Patent Application No. 60-225643.
No., Patent Application No. 1983-225644, Patent Application No. 1982-225
No. 645 or Japanese Patent Application No. 60-225646, a
A photoreceptor has been proposed in which an a-3iO:H transition layer is provided between a -3iO:H charge transport layer and an a-3i:H charge generation layer.

According to this photoreceptor, due to the presence of the transition layer, the surface potential decreased by a low electric field (100 to 150
(2) It is possible to reduce the decrease in sensitivity in (absolute value).

The present inventor conducted various studies on this photoreceptor and found that there is still room for improvement in terms of preventing a decrease in sensitivity and suppressing residual potential. That is, a-3i
Although the transition layer between the O:H charge transport layer and the a-3i:H charge generation layer can reduce the energy gap between both layers, it is still insufficient in terms of sensitivity and residual potential. Do you get it.

Particularly, the object of the present invention is to provide a photoreceptor, such as an electrophotographic photoreceptor, which reduces changes in charging potential during repeated use, reduces dark decay and residual potential, and improves photosensitivity. It's about doing.

D9 Structure of the invention and its effects, that is, the present invention provides a photosensitive material having a charge transport layer made of amorphous hydrogenated and/or halogenated silicon oxide and a charge generation layer made of amorphous hydrogenated and/or halogenated silicon. In the body, the charge generation layer contains an element of Group I or V of the periodic table, and is an amorphous hydrogenated and/or non-doped amorphous layer that does not contain these elements.
Alternatively, the present invention relates to a photoreceptor characterized in that an intermediate layer made of silicon halide is provided between the charge transport layer and the charge generation layer.

According to the photoreceptor of the present invention, the energy gap between the charge transport layer and the charge generation layer is significantly alleviated by the non-doped intermediate layer. In other words, the energy gap between both layers is reduced by the intermediate layer to the width of an ordinary human being, so electrons or holes generated during light irradiation can easily move from the photoconductive layer to the charge transport layer, resulting in photoelectric conversion. The rate or photosensitivity can be greatly improved, and the residual potential can also be reduced. Since the charge generation layer (and more preferably the charge transport layer) contains a predetermined amount of the above-mentioned Group I or V element of the periodic table, it has sufficient charging characteristics and is suitable for practical charging with low dark decay. A high electric potential is obtained, and the residual electric potential is also reduced.

Since the photoreceptor of the present invention is of a functionally separated type in which the charge generation layer and the charge transport layer are separated, it has good stability (and sufficient durability during repeated use).

In the photoreceptor of the present invention, in particular, if an amorphous hydrogenated and/or halogenated silicon oxide layer is present as a blocking layer on the substrate side, injection of carriers from the substrate can be effectively prevented, and other Since the dark resistance of the layer is increased by impurity doping, the charged potential can be maintained and dark decay can be further reduced. Furthermore, since the charge transport layer is also formed of a similar silicon oxide layer, the charge transport ability is good, and the provision of a surface modification layer of an inorganic material (especially amorphous silicon carbide or silicon nitride) on the outermost surface improves durability and Stability etc. are further improved.

The invention will now be illustrated in detail with reference to the drawings.

For example, as shown in FIG. 1, the photoreceptor according to the present invention has an a-3iO:8 layer 2 as a charge transport layer doped with a group A or VA element of the periodic table on a conductive support substrate 1. , an a-3iOsH layer 3 as a transition layer similarly doped with impurities, and a non-doped a-3iOsH layer 3 as an intermediate layer.
A 3i:H layer 4 and an a-3isH layer 5 as a charge generation layer doped with a group 1 [A or VA element of the periodic table] are sequentially laminated, and further, a substrate 1 and an a-3iO:8 layer 2 N-type or P-type (or even P-type) as a blocking layer doped with elements of group VA or group II
Type 2) A-3tOsH layer 6 is provided. In the example shown in FIG. 1, a surface modification layer (for example, a-
3iC:H or a-3iN:H layer) 7 is provided.

The a-3iO:H layer 6 greatly contributes to preventing the injection of carriers from the substrate 1 and maintaining a sufficient surface potential, and therefore has N-type conductivity due to the inclusion of a VA group element or a IIIA group element. It is important to exhibit P-type conductivity by containing . In addition, its thickness is 400 ~ 3 μm
It is desirable that

a-3iO:8 Layer 2 mainly has potential retention and charge transport functions, and is preferably formed to a thickness of 5 to 30 μm. Charge generation layer 5 generates charge carriers in response to light irradiation. It is desirable that the thickness is 1 to 30 μm. Furthermore, a-3iC:H or a-3iN:
The H layer 7 improves the surface potential characteristics of the photoreceptor, maintains the potential characteristics over a long period of time, maintains environmental resistance (prevents the influence of humidity, atmosphere, and chemical species generated by corona discharge), and has high surface hardness. It has the functions of improving rigidity resistance, improving heat resistance when using a photoreceptor, and improving thermal transferability (especially adhesive transferability), and acts as a surface modification layer.

In this photoreceptor, a-3iO/a-3t:H/a
Not only does it have the feature of having a -5iC laminated structure,
Since the a-3iO:H blocking layer is made P-type or N-type by doping with Group IIA or VA elements of the periodic table, carriers (electrons or holes) can be effectively injected from the substrate side during positive or negative charging. thwarted. Moreover, in addition to this, the charge transport layer 2 and the transition layer 3 (charge generation layer 5,
Furthermore, the fact that the surface modified layer 7) is doped with a group 111A element or a group VA element of the periodic table greatly contributes to improving each electrostatic property, as will be described later.

However, layer 2.3 does not necessarily have to be doped with the above elements.

The optical bandgap between the a-3iOsH layer 2 and the charge generation layer 5 is, for example, 0.3 eV or more, but the a-3iO:H layer 3 is preferably formed between these two layers as a transition layer with a thickness of 400 nm or more. 2 μm and the transition layer 3
and the charge generation layer 5, a non-doped 3 isH layer is formed as the intermediate layer 4 with a thickness of less than 3 μm, preferably 200 to 1 μm.
It is set in. It is important that the presence of the intermediate layer 4 and the transition layer 3 suppresses the energy barrier between the a-3iOsH layer 2 and the photoconductive layer 5 to 0.3 eV or less. Here, the above-mentioned "non-doped" means that the amount of impurities is 0.01 capacitance pp+m or less.

Figure 2 shows how the optical energy gap changes depending on the oxygen atom content of a-3iO:H. If controlled, layer 2
And the energy gap of three layers can be formed with good controllability.

In addition, the oxygen content of the transition layer 3 is at least 0.5 atomic% lower than the oxygen content of the charge transport layer 2 (by doing so, the photoconductive layer 5, transition layer 3, intermediate layer 4, charge transport The energy barrier between layers 2 can be reduced to 0.3 eV or less.The oxygen content of each layer is also important for controlling this band gap and maintaining the surface charge potential by increasing the resistance. Also, when S i 10 = 100 atomic%, the oxygen content of layer 2 is 0.1 to 10 atomic% (preferably 0.5 atomic%).
~3 atomic%).

The oxygen content of layer 3 is preferably 0.05 to 9.5 atomic%.

The effect of providing the transition layer 3 and intermediate layer 4 in this way will be explained in detail with reference to FIGS. 3 and 4.

FIG. 3 shows an example in which the blocking layer 6 is of N1 type and the photoreceptor is negatively charged. A gap (difference between conduction bands CB) ΔH exists. Between these two layers, there is a transition layer 3 and an intermediate layer 4 exhibiting an intermediate energy level, and the energy gap between the transition layer 3 and intermediate layer 4 and both layers 2.5 appears to be large. The above ΔE is much smaller (eg, about % or less). Therefore, when the surface is negatively charged and then irradiated with light, electrons among the carriers generated in the charge generation layer 5 easily move to the intermediate layer 4, which has a lower energy level than the charge transport layer 2, and transition to the next stage. It moves to layer 3 and then to the next charge transport layer 2. At this time,
Because the energy gap or energy barrier between each layer 5-4.4-3.3-2 is much smaller than 0.3 eV, electrons are transferred from the charge generation layer 5 to the charge transport layer 2 and then to the substrate 1.
It becomes easier to move smoothly from side to side.

This is particularly effective under low electric fields (on the order of 100-150 V) (ie, the gradient between the potentials of each band is reduced). On the other hand, the generated holes can easily move to the surface, so that the photoreceptor has sufficient photosensitivity and fewer residual phenomena. On the other hand, when the intermediate layer 4 and even the transition layer 3 are not provided, electrons cannot easily move to the charge transport layer 2 due to the energy level gap or the energy barrier Δ decreases, resulting in deterioration of photosensitivity. In addition, substrate 1
Holes are about to be injected from then on, but the energy gap (difference in valence span VB) between the substrate 1 and the blocking layer 5 is because the blocking layer is N-shaped and the valence span is shifted downward. In addition, since the size of the hole is large, hole injection is substantially prevented, and the retention of surface potential is not affected.

FIG. 4 shows an example in which the blocking layer 6 is made into a P+ type and is used for positive charging. In this case as well, a transition layer 3 and an intermediate layer are provided between the charge transport layer 2 and the charge generation layer 5 in the valence pant VB. 4, the energy gap between each layer becomes smaller. Therefore, holes generated in the charge generation layer 5 during light irradiation move to the intermediate layer 4, the transition layer 3, and further to the charge transport layer 2, and the efficiency of movement toward the substrate 1 side increases, resulting in good photosensitivity. Therefore, the remaining power will be reduced. Further, when charging, electrons try to be injected from the substrate 1, but since the blocking layer 5 is P'' type, the substrate 1
Since a sufficient energy barrier is formed between the two, electron injection is substantially prevented, and the surface potential can still be maintained high.

Additionally, as an additional effect of providing the transition layer 3,
If the charge transport layer 2 with a high oxygen content is in direct contact with the charge generation layer 5, the bond between them will be weak and the bonding properties will be insufficient, but the transition layer 3 with a relatively low oxygen content
a-3iO:H and a-3i
: Good bonding with H.

Next, an apparatus (glow discharge CVD apparatus) that can be used to manufacture a photoreceptor according to the present invention will be described with reference to FIG.

In a vacuum chamber 62 of this device 61, a drum-shaped substrate 1 is set so as to be vertically rotatable, and a heater 65 can heat the substrate 1 from the inside to a predetermined temperature. A cylindrical electrode 67 with a gas outlet 63 is disposed around and facing the substrate 1, and a glow discharge is generated between the electrode 67 and the substrate 1 by a high frequency power source 66. In addition, 72 in the figure is S
iH.

Or source of gaseous silicon compound, 73 is 0! or a source of gaseous oxygen compounds, 74 is a source of hydrocarbon gas such as CH, or a source of nitrogen compound gas such as NH, N, etc., 75
is a carrier gas supply source such as Ar, 76 is an impurity gas (for example, BzHb or PH,) supply source, and 77 is each flow meter. In this glow discharge device, first, the surface of a support, for example, an Af substrate 1, is cleaned, and then placed in a vacuum chamber 62, and the gas pressure in the vacuum chamber 62 is adjusted to 10-' Torr, and the air is evacuated. and keep the substrate 1 at a predetermined temperature, particularly 100 to 350°C (preferably 150 to 300°C).
Heat and hold. Then, using a high purity inert gas as a carrier gas, 5iHa or a gaseous silicon compound, B
zHh (or PH,), CI (or N!) are appropriately introduced into the vacuum chamber 62, and a high frequency voltage (for example, 13
．． 56 MHz). As a result, each of the above-mentioned reaction gases is decomposed by glow discharge between the electrode 67 and the substrate 1,
Boron heavily doped a-3iO:H, boron doped a-3iO:H, boron-doped a-3iO:H, non-doped Si:H, boron-doped a-3i:H, boron-doped or non-doped a-3iC:H or a-3i
N:H is deposited successively (ie corresponding to the example of FIG. 1) on the substrate as layer 6.2.3.4.5.7 above.

Regarding the above a-3iC:H or a-3iN:H layer 7, it has been found that it is also important to select its carbon or nitrogen composition in order to exhibit the above-mentioned effects. The composition ratio is a-3it -xCx: H or a-3i, -yNy
: If expressed as H, especially 0.1≦X≦0.7 (if S i + C = 100 atomic%, the carbon atom content is 10 atomic% to 70atOII
liC%), similarly 0.05≦y≦0.7
(If Si+N=100 atomic%, the nitrogen atom content is preferably 5 to 70 atomic%). That is, if 0.1≦X or 0.05≦y, the optical energy gap will be approximately 2, OeV or more, and due to the optically transparent window effect for visible and infrared light, most of the irradiated light will be a
-3isH layer (charge generation layer) 5 is reached.

Conversely, when x<0.1, a portion of the light is absorbed by the surface layer 6, and the photosensitivity of the photoreceptor tends to decrease. Also, X is 0
．． If it exceeds 7, most of the layer becomes carbon or nitrogen, and the optical properties and film strength decrease.
Since the deposition rate when forming an iN:H film by a glow discharge method decreases, it is preferable that X≦0.7.

Therefore, this a-3iO:H layer 2 maintains a high surface potential at a practical level, efficiently and quickly transports the charge carriers generated in the a-3tsH layer 5, and functions to provide a photoreceptor with high sensitivity and no residual potential. There is. This a-3iO:H layer 2 is
it −xOx: When expressed as H, 0.001≦X≦
0.1 (oxygen atom content is 0, latomic%~1
0atomic%: However, Si+0=100ato+m
ic%). The oxygen atom content of the transition layer 3 is preferably 0.05 to 9.5 atomic%.

Further, the oxygen content of the a-3iO:H charge blocking layer 6 is also the same as that of the layer 2 (preferably 3#atomic% or less).

The above a-3iCsH layer and a-3iN:H layer, a-3
Both the t:H layer and the a-3iO:H layer need to contain hydrogen, but if they do not contain hydrogen, the charge retention characteristics of the photoreceptor will not be practical. Therefore, the hydrogen content is 1 to 40atO1lIiC%
(Furthermore, it is desirable to set it as 10-30 atomic%). The hydrogen content in the charge generation layer 5 is essential to compensate for dangling bonds and improve photoconductivity and charge retention, and is usually 1 to 40 aton+ic.
%, and more preferably 20 atomic% or less.

In this way, when forming each layer by glow discharge decomposition,
It is necessary to appropriately select the flow rate ratio of diborane or phosphine gas and silicon compound (eg monosilane).

a-3iO: PH2 (phosphine) when forming the H layer 6
When the flow rate ratio of SiH4 and SiH4 (monosilane) is changed, P
In the region where N-type conductivity is stabilized as a result of phosphorous doping with H, PHs/S is required to form a blocking layer that can sufficiently prevent carrier injection from the substrate.
The flow rate ratio of iH4 is preferably 1 to 5000 pp+m. In addition, in the case of P-type conversion by boron doping, BZ
It is preferable to perform glow discharge decomposition at HA/S i H,=20 to 5000 ppm.

On the other hand, the amount of boron doping performed when forming layer 2.3.5.7 above needs to be appropriately selected in order to obtain the desired dark resistance value. and B, H in 3.

/S i H4≦20 capacity ppm, and 2
It is even better to set the capacity to 1)I)II. If it exceeds this range, electrical properties such as charging ability will deteriorate. In the layer 5, an element of group 111A of the periodic table, for example, BzHi is replaced with B2H
1/ S i Ha = 0.1 to 100 ppm by volume
(furthermore, 0.2 to 50 ppm by volume), and in layer 7, a-
When 3iC:H, for example, Bg Hh / S i H
a = 0.1-20 ppm by volume.

When a-3iN:H, for example, BzH6/5iHa=1
It is preferable to set the amount to 1000 ppm by volume.

However, the optimum range of the above-mentioned impurity doping amount depends on the N, C, H content of the layer, and therefore is not necessarily limited to the above-mentioned range.

In the example explained above, in order to compensate for dangling bonds, a halogen such as fluorine is introduced into a-3i instead of the above-mentioned H or in combination with H,
a-3t:F, a-3t:H:F, a-3iC:F%a
-5iC:H:F can also be used. In this case, the amount of fluorine is preferably 0.01 to 20 atomic%.
~10 atomic% is more desirable.

Although the above manufacturing method is based on a glow discharge decomposition method, the photoreceptor can also be manufactured by a vapor deposition method, a sputtering method, an ion blating method, or the like. In addition to SiH4, the reaction gases used include Si, H, SiH.
F3, SiF4 or its derivative gas, Cz other than CH4
Lower saturated or unsaturated hydrocarbon gases such as H, C, H8 can be used. As an oxygen source, N, O, No, C
Gases containing oxygen such as O□ and CO can be used.

In addition to boron and aluminum, the impurities to be doped include other Group NlA elements of the periodic table such as gallium, indium, and thallium, and other Group VA elements of the periodic table such as arsenic other than phosphorus, nitrogen, antimony, and bismuth. Available for use. When this Group VA element of the periodic table is included in the charge generation layer, it is recommended that the capacitance be 0.1 to 100 pp+*, and even better that the capacitance be 0.2 to 50 ppa+. , AI! , (CH3)a ,
Ga(CH3)x, In(CH3)3BF3,
Aj! (C2Hs)ff, Ga (cz Hs
)! , BClx , BBrs , B It , NH:I
,PH3,AsH,,5bHt,PClz,AS
F3.5bCI! ,,,PF*,P(CH3L,
P (Ct I(s )3 etc., but Bz
Hi, PHs are preferred.

Next, each layer of the photoreceptor described above will be explained in more detail.

Saku141Ll This a-3iO:H layer 2 has both the functions of potential retention and charge transport, has a dark resistivity of 10'3 Ω-1 or more, has high electric field resistance, and maintains energy per unit film thickness. Since the potential applied thereto is high and the electrons or holes injected from the photosensitive layer 5 exhibit large mobility and lifetime, the charge carriers are efficiently transported (toward the support 1 side).

Further, since the size of the energy gap can be adjusted by adjusting the composition of oxygen, charge carriers generated in the photosensitive layer 5 in response to light irradiation can be efficiently injected without creating a barrier. In addition, a-3iO:H also has the property of having good adhesion and film formation with the support 1, for example, the A1 substrate.

This a-3iO:H layer 2 maintains a high surface potential at a practical level, efficiently and quickly transports the charge carriers generated in the a-3isH layer 5, and has the function of making a photoreceptor with high sensitivity and no residual potential. be.

In order to fulfill these functions, the thickness of the a-3iO:H layer 2 is preferably 5 μm to 30 μm in order to apply a dry development method using the Carlson method, for example. If the film thickness is less than 5 μm, it is too thin and the surface potential necessary for development cannot be obtained, and if it exceeds 30 μm, the film forming time becomes long and the residual potential becomes high. However, this a-3
Even if the thickness of the iOrH layer is made thinner than that of the Se photoreceptor (for example, ten-odd μm), a surface potential at a practical level can be obtained.

[1] As mentioned above, this a-3iO:8 layer 3 functions as a transition layer for smooth carrier movement, and has the effect of reducing the energy gap between the layers through which carriers move, a-3tO:H and a-3i:H
This makes it easier to bond with the material and improves the bonding characteristics. Further, since this layer 3 has the same composition as layer 2, it is easy to form a film, and it is also easy to create an energy level intermediate between layers 2-5.

The thickness of the a-3iOsH layer 3 is preferably selected to be between 400 and 2 μm, but if the thickness is less than 400, the thickness of the a-3iO:H layer 2 and a-
It becomes difficult to separate the 3i:H layer 5 with the above-mentioned profile, and if the thickness exceeds 2 μm, it is rather impractical. Note that this transition layer may include multiple a-3i layers as needed.
It may be formed of a laminate of O:H layers, and the energy level described above may be changed in multiple steps.

This layer 6 forms an energy barrier (gap) between it and the substrate that can sufficiently block the injection of carriers (electrons or holes) from the substrate 1. It has the function of eliminating the neutralization phenomenon of , maintaining the surface potential, and by extension, maintaining good charging characteristics. For this purpose, a-3
It is important that the iO:H layer 6 is doped with impurities to change the N-type to P-type as described above. Further, the film thickness is preferably selected to be 400 to 3 μm (or even 400 to 165 μm). No effect on less than 400 people, 3μ
If it exceeds m, the residual potential tends to increase. Also,
The oxygen content of this blocking layer is a-3iO:H layer 2
may be the same as

Raw M This layer 4 shows an intermediate energy between layers 2-5, and especially when using a negative charge, the conduction band shows an intermediate level between layers 3-5. There is tier 3 in the level. ), and when positively charged, the valence punt shows an intermediate level between layers 3-5 (layers 2-4
There is layer 3 at the intermediate level. ). And this middle layer 4
The thickness is preferably 0 to 3 .mu.m (if it exceeds 3 .mu.m, the sensitivity will actually decrease), but it is even better to have a thickness of 200 to 1 .mu.m.

a-3i:H This a-3tsH layer 5 has high photoconductivity over the entire visible light region, and is ρD/ρL (dark resistivity/during light irradiation Resistivity) is the highest ~104. By using this a-3t:H as a photosensitive layer, it is possible to create a photoreceptor that is highly sensitive to light in the entire visible region.

In order to absorb visible light without waste and generate charge carriers, the thickness of the a-3i:H layer 5 is preferably 1 to 3 um. When the film thickness is less than 1 μm, all of the irradiated light is not absorbed, and a portion of it reaches the underlying a-3iO:H layer 2, resulting in a significant decrease in light intensity. Also, a-3t
:The H layer 5 does not need to be thicker than the thickness required for light absorption as a photosensitive layer, and a thickness of 30 μm is sufficient. Also,
By including N in this layer 5, an element of Group mA or Group VA of the periodic table, the residual potential can be reduced without deteriorating the sensitivity and charging ability. For this purpose, it is desirable to use the same element as B, H6/SiH4 or PH1/SiH, with a flow rate ratio of 0.01 to 10 ppm by volume. 0
．． If the capacitance is less than 0.01 ppm, the sensitivity and residual potential will be insufficient, and if the capacitance exceeds 10 ppm, a decrease in sensitivity, charging, and performance are likely to occur.

1. This surface modification layer 7 (see FIG. 1) is desirably provided in order to modify the surface of the photoconductor and make the a-3i photoconductor practically superior. That is, it enables the basic operations of an electrophotographic photoreceptor, such as charge retention on the surface and attenuation of the surface potential due to light irradiation. Therefore,
The repeated characteristics of charging and optical attenuation are very stable, and good potential characteristics can be reproduced even if left for a long period of time (for example, one month or more). On the other hand, in the case of a photoreceptor having a-3i:H as its surface, it is easily affected by humidity, air, ozone atmosphere, etc., and the potential characteristics change significantly over time. In addition, the surface-modified layer made of inorganic materials such as a-3iC:H has high surface hardness, so it has abrasion resistance during processes such as development, transfer, and cleaning.It also has good heat resistance, so it can be used for adhesive transfer, etc. A process that applies heat can be applied.

The surface modified layer may be made of Sin, Sin, Al1.
O,,Taz os,CeO□,Zr0t.

Tie, , MgO1ZnO, PbO5SnO,.

Selected from the group consisting of MgF, ZnS, and amorphous silicon carbide or nitride (however, it is preferable that these amorphous silicon compounds contain the above-mentioned hydrogen or fluorine, but they do not necessarily need to contain them.) It is possible to use a material consisting of at least one species. The thickness of the surface modified layer 7 should be between 200 and 30,000 layers (preferably 1,000 and 10,000 layers); if the thickness is less than 200 layers, it becomes difficult to charge the surface due to the tunnel effect, and dark decay and light Sensitivity is likely to decrease,
Moreover, when the number of people exceeds 30,000, the residual potential becomes high and the photosensitivity tends to decrease.

E. Example Next, an example in which the present invention is applied to an electrophotographic photoreceptor will be specifically described.

An electrophotographic photoreceptor having the structure shown in FIG. 1 was prepared on an A2 support by a glow discharge decomposition method. First, a clean A2 support with a smooth surface was placed in a reaction (vacuum) chamber of a glow discharge device. After evacuating the reaction tank to a high vacuum level of 10-6 Torr and heating the support to 200°C, high purity A
Introduce r gas, apply high frequency power with a frequency of 13.56 MHz and a power density of 0.04 W/cii under a back pressure of Q, 5 Torr, and pre-discharge for 15 minutes or Bz H
By glow discharge decomposition of the b gas, the a-3iO:H layer that prevents carrier injection, as well as the a-3fO:H layer and transition layer that have potential holding and charge transport functions, are
The film was formed at a deposition rate of 1 person/ll1n. Further, SiH4 and B and H were added as necessary, with Ar being used as a carrier gas without supplying N and O.

was subjected to discharge decomposition to form a non-doped a-33:H intermediate layer and a boron-doped a-3t:H photosensitive layer, and then a surface modification layer was further provided to complete an electrophotographic photoreceptor.

Regarding such a photoreceptor, the composition of each layer was changed as shown in Table 1.2 below, and the following measurements were carried out.

Charge potential Vo (V): Using a modified tl-Bix 2500 machine (manufactured by Konica ■),
Photoconductor inflow current 200uA, 36 under no exposure condition
0 Surface potential immediately before development measured with an SX type electrometer (manufactured by Trek).

Half-decreased exposure amount E'A (41!ux-sec): Using the above device, a dichroic mirror (manufactured by Koshinko Co., Ltd.) sharply cuts long wavelength components of 620 nm or more of the image exposure wavelength, and the surface potential is set to 500 V. The amount of exposure required to reduce the amount of light by half from 250cm to 250cm. (The exposure amount was measured with a 550-1 photometer (manufactured by EC; and G Company)) Residual potential VR (v): After charging to 500μ using the above device, 400n
Illuminate the static electricity removal light with a peak at m for 301 ux-sec'1
Surface potential after 1.

Overall rating: 20 Good Δ Slightly poor, but no problem The charging characteristics are also very good. 1! II. When a non-doped intermediate layer is provided in a state in which the charge generation layer is doped with impurities (Examples 1 to 14), compared to the case where this is not provided (Comparative Examples 1.3.5.7.9.11.13) In this case, if a transition layer is provided as in Example 2.4.6.8.10.12.14, the sensitivity, charging potential, and residual potential can all be reduced. A good value is obtained.Comparative Example 2 in which a transition layer is provided but an intermediate layer is not provided.
In the case of 4.6.8.10.12.14, the residual potential is slightly worse.

Note that as the amount of impurity doping in the charge transport layer is increased, the residual potential tends to decrease, but conversely, the charging ability also tends to decrease.

[Brief explanation of drawings]

The drawings illustrate the present invention, in which Fig. 1 is a cross-sectional view of a part of an electrophotographic photoreceptor, Fig. 2 is a graph showing the energy gap of a-3iO:H depending on the oxygen content, and Fig. 3.4. The figure is an energy band diagram of the photoreceptor, and FIG. 5 is a schematic sectional view of a glow discharge apparatus for manufacturing the photoreceptor. In addition, in the symbols shown in the drawings, 1...
...Support (substrate) 2...A-3iO doped with impurities
:H charge transport layer 3... a-5iO doped with impurities
:H transition layer 4...Non-doped a-5t:H intermediate layer 5
...... impurity-doped a-5i:H
Charge generation layer 6: a-3iO doped with impurities
:H charge blocking layer 7 ......a -S i C: H or a
-3iN:H surface modification layer. Figure a-5i1-xOx: l-1

Claims (1)

[Claims] 1. A charge transport layer made of amorphous hydrogenated and/or halogenated silicon oxide, and an amorphous hydrogenated and/or
Or a photoreceptor having a charge generation layer made of silicon halide, wherein the charge generation layer contains an element of Group III or Group V of the periodic table, and an amorphous hydrogenated and/or halogen containing no element. 1. A photoreceptor characterized in that an intermediate layer made of silicon oxide is provided between the charge transport layer and the charge generation layer.