JPH01206356A - Photosensitive body - Google Patents

Abstract

PURPOSE:To obtain the photosensitive body which withstands repetitive use and with which good images are obtainable by incorporating a carbon atom and oxygen atom into a surface reformed layer and doping an impurity element under specific conditions therein. CONSTITUTION:This photosensitive body has a charge generating layer 43 consisting of amorphous silicon hydride and/or halide and the surface reformed layer 45 deposited on the surface thereof. The surface reformed layer 45 consists of the amorphous silicon hydride and/or halide contg. the carbon and oxygen atoms and contg. the impurity element of group VA of the periodic table as well. The content of the oxygen atom is specified to 1-20atm.% (where the total content of the silicon atom and the carbon atom and oxygen atom is designated as 100atm.%) and the surface reformed layer 45 doped with the impurity element under the conditions expressed by formula I at the time of forming the surface reformed layer 45 is formed. The photosensitive body which withstands the repetitive use and with which the good images are obtd. is thereby obtd.

Description

[Detailed description of the invention]

B. Industrial Application Field The present invention relates to a photoreceptor, for example, an electrophotographic photoreceptor. Conventional technology Conventionally, amorphous silicon (
Electrophotographic photoreceptors using a-8i) as a matrix have been proposed in recent years. Since a-3i has so-called dangling bonds, amorphous hydrogenated silicon (a-3i: H ) has been proposed. However, photoreceptors with an a-8i:H surface are susceptible to surface chemical stability, such as the effects of long-term exposure to the atmosphere or moisture, and the effects of chemical species generated by corona discharge. , has not been sufficiently investigated so far. For example, items that have been left for more than a month will be affected by moisture.
It is known that the receptor potential is significantly reduced. On the other hand, amorphous hydrogenated silicon carbide (hereinafter a-8iC:H
It is called. ), its manufacturing method and existence are described in “Ph1l. Dark resistivity (1012~
It is known that the optical energy gap changes over a range of 1.6 to 2.8 eV depending on the amount of carbon. However, there is a drawback that long wavelength sensitivity becomes poor due to widening of the band gap due to the inclusion of carbon. An electrophotographic photoreceptor combining such a-8iC:H and a-8i:H has been proposed, for example, in Japanese Patent Application Laid-Open No. 115559/1983. According to this, a-8i:
An a-8iC:H layer is formed as a surface modification layer on a charge generation layer made of H. However, when the present inventor investigated the above-mentioned known photoreceptor, it was found that even if a surface modification layer was provided, it was still not as effective as expected, and image deletion was particularly likely to occur. C1 Object of the invention An object of the present invention is to provide a photoreceptor that can withstand repeated use and produce good images. It has a photoconductive layer made of hydrogenated and/or halogenated silicon, and a surface modified layer deposited on the surface of this photoconductive layer, and this surface modified layer contains carbon atoms and oxygen atoms. and is made of amorphous hydrogenated and/or halogenated silicon that also contains an impurity element of Group VA of the periodic table, and the amount of oxygen atoms is 1 to 2.
0 atm% (however, the total amount of silicon atoms, carbon atoms, and oxygen atoms is 1100 atm%), and when the impurity element forms the surface modified layer by glow discharge decomposition, under the following conditions. The present invention relates to a photoreceptor in which the surface modification layer is doped. According to the present invention, since the surface modified layer contains carbon atoms and oxygen atoms, the mechanical strength and optical band gap (Eg, opL) of the layer are poor, and image quality deterioration due to white streaks etc. This results in excellent printing durability. Moreover, the surface modified layer contains the above-mentioned impurity elements.
Since it is doped at a rate of 10 vol ppm, image deletion can be greatly reduced during image formation. This is considered to be because the surface resistance and impurity level of the layer are appropriately set by the impurity element. E. Examples Hereinafter, the present invention will be explained in detail with reference to examples. FIG. 1 shows an a-8i electrophotographic photoreceptor 3 according to this embodiment.
9. This photoreceptor 39 is provided on a drum-shaped conductive support substrate 41 such as a kl as required.
-Si-based charge blocking layer 44 and a-3i:
A photoconductive layer 43 consisting of H (without impurity doping or made intrinsic) and a-8i (containing C and O)
It has a structure in which a surface modified layer 45 made of CO):H is laminated. The charge pulling layer 44 has a-8i :H,, a-
It may consist of 8iC:H or a-3iN:H, and may be doped with an element from group [11A or VA of the periodic table. Further, the photoconductive layer 43 may also be doped with similar impurities. The photoconductive layer 43 has a dark resistivity ρ
The ratio of D to the resistivity ρL upon irradiation with light is sufficiently large as an electrophotographic photoreceptor, and the photosensitivity (particularly to light in the visible and infrared regions) is good. What should be noted here is that the surface modified layer 45 is made of a-8iC:H or a-8i(CO):H containing C and O. As a result, the surface modified layer 45
The mechanical strength of the material is improved, and the optical bandgap is also improved. Regarding the composition of the surface modified layer 45, 10 atm%≦(C'+O:)≦1100at%lat
m%≦

[0]≦20atm% (However, (S i ) 10 (C) + (0) = 100
40 atm%≦CC+O:]≦70 atm%latm%
≦

[0]≦10atm% (However, (Si:)+CC]+(0]=100atm%
) (here, atm % represents the percentage of the number of atoms). If the content of C+0 is too small, the effect of improving scratch resistance will be poor, and if it is too large, the amount of Si will decrease and semiconductor properties will be easily lost. In addition, when the surface modified layer contains a small amount of oxygen atoms, the optical band gap is improved and the resistance to image fading is improved; however, if the amount is too large, the scratch resistance is deteriorated. Another noteworthy point of this photoreceptor is that the surface modification layer 45 is doped with Group VA elements of the periodic table, preferably from 10@-1 to 10 (capacity apl). These impurity elements can significantly reduce image deletion. That is, the amount of impurity elements is 10-
If the capacitance is less than 3 pp, it is too small, and if it exceeds 10 pp, it is too high, and in both cases, sufficient surface resistance cannot be obtained and image blurring occurs significantly. The thickness of the surface modified layer 45 is preferably 200 to 30,000 times, and more preferably 1,000 to 10,000 times. If the film thickness is too large, the residual potential VR will become too high and the photosensitivity will decrease, resulting in a-3i
It is easy to lose good characteristics as a photoreceptor. Furthermore, if the film thickness is too small, charges will not be charged on the surface due to the tunnel effect, resulting in increased dark decay and decreased photosensitivity. The photoconductive layer 43 as a photosensitive layer is made of a-8i:H (its composition is 5 to 40 atm% of H).
When containing halogen in place of or in combination with H, 5 to 40 atm% of halogen, or H
The total amount of halogen and halogen is preferably 5 to 40 atm%. This photoconductive layer 43 contains impurities,
In particular, it is preferable to dope an element of group 11IA or vA of the periodic table. For example, during glow discharge described below, [l32H6:
) / CS i Ha ] = 10-' ~ 100 (
Preferably 10-2 to 10) Capacity Hayabusa, CPH, M (Si
H4) = 10' to 100 (preferable (2 or 10-2 to 1
0) It is good as a container. Further, the thickness of this layer 43 is preferably 5 to 100 μm, preferably 10 to 30 μm. If the thickness of the photoconductivity/m43 is too small, sufficient charging rotation will not be achieved, and if it is too thick, the residual potential will increase, making it unsatisfactory for practical use. Further, the charge blocking layer 44 sufficiently prevents the injection of electrons from the substrate 41, and in order to improve sensitivity and charging ability, the charge blocking layer 44 is doped with an element of group 1I [A of the periodic table (for example, boron)] by glow discharge decomposition. Then, it becomes P type (and further P type). It is desirable to control doping characteristics as follows by changing the composition of the blocking layer. a-8i: H (H content! 5-4 oatm%): CB 2
H6:)/(S iH4] = 10-' to 104 volume 4 (furthermore 10-1 to 102 volume 1 pp-) [PJ:]/[
:SiH4] = 10-5~10'capacity-〇further 10
~10 volume 1 pIn) a-3iC:H (H content 5-50 atm%, C content 5-100 atm%): [B2H6]/(SiH4:] = 10-5-10' Furthermore, 10-1 ~ 10' Yong Shishi) CPH, ]/C3iH4) = 10-5 ~ 10' Capacity Exp (
Further IC&'K 10-' ~ 10j volume fiP) a-8i
N:H (H content 5-50 atm%, N content 5-50 atm%
60atm%): [B2H6':]/(SiH4]=10-'~10'
volume 1tpp (further 10-1 to 10' volume) [J'H5:l]/[81H4) = 10-' to 10'
The blocking layer 44 preferably has a thickness of 100 A to 2 μm. If the thickness is too small, the blocking effect will be weak, and if the thickness is too large, the charge transport ability will tend to deteriorate. Note that each of the above layers needs to contain hydrogen. In particular, the hydrogen content in the photoconductive layer (charge generation layer) 43 is necessary to compensate for dangling bonds and improve photoconductivity and charge retention. In addition to poron, other impurities to be doped include A
Elements of group mA of the periodic table such as l, Ga, In, and TA can be used, and in addition to phosphorus, elements of group VA of the periodic table such as As and sb can be used. Next, a method for manufacturing the above-mentioned photoreceptor (for example, drum-shaped) and an apparatus therefor (glow discharge apparatus) will be explained with reference to FIG. A drum-shaped substrate 41 is set rotatably vertically in a vacuum chamber 52 of this device 51, and a heater 55 is used to rotate the substrate 41.
can be heated to a predetermined temperature from the inside. A cylindrical high frequency electrode 57 with a gas outlet 53 is disposed around and facing the substrate 41, and a glow discharge is generated between the electrode 57 and the substrate 41 by a high frequency power source 56. In addition, 62 in the figure is a supply source of SiH4 or gaseous silicon compound, 63 is a supply source of hydrocarbon gas such as CH, 64 is a supply source of nitrogen compound gas such as N2, and 65 is a supply source of oxygen compound gas such as 02. Supply source, 66 is a carrier gas supply source such as Ar, 6
7 is an impurity gas (for example, B2H6) supply source, and 68 is each flow meter. In this glow discharge device, first, the surface of a support, for example, an Al substrate 41, is cleaned and then placed in a vacuum chamber 52, and the gas pressure in the vacuum chamber 52 is set to 10'T.
The substrate 41 is heated to a predetermined temperature, particularly 100 to 350°C (preferably 150 to 350°C).
Heat and hold at 300°C. Next, using a high-purity inert gas as a carrier gas, 5iI (4 or gaseous silicon compound, CH4, N2, CO2, 02, etc.) is introduced into the vacuum chamber 52 as appropriate, and the reaction is carried out under a reaction pressure of, for example, 0.01 to 10 Torr. The high frequency power supply 56 generates a high frequency voltage (for example, 13
．． 56MHz) is applied. As a result, each of the above reaction gases is decomposed by glow discharge between the electrode 5T and the substrate 41, and a-3i:H, a-8i:H, and a-8iCO:H are converted to 1-44.43.45 on the substrate. (i.e. corresponding to the example of FIG. 1, for example). In the above manufacturing method, the support temperature is set at 100 to 350°C in the step of forming the a-8i layer on the support, so the film quality (especially electrical properties) of the photoreceptor can be improved. . In addition, when forming each layer of the above a-3i photoreceptor,
In order to compensate for dangling bonds, it is necessary to use halogens such as fluorine instead of H, or in combination with H.
Introduced in the form of iF4 etc., a-8i:F, a-3i:
H:F, a-8iN:F, a-8iN:H:F,
It can also be a-sic:F', a-8iC:H:F, etc. Hereinafter, the present invention will be described with reference to specific examples. A finely crushed electrophotographic photoreceptor as shown in FIG. 1 was prepared on a drum-shaped support by a glow discharge decomposition method. That is, first, after cleaning the surface of a support, for example, a drum-shaped substrate 41 with a smooth surface, it is placed in a vacuum chamber 52 shown in FIG.
Torr, and exhaust the air, and keep the substrate 41 at a predetermined temperature, particularly 100 to 350°C (preferably 150°C).
~300°C) Maintain VC heating. Next, high purity A
r gas is introduced as a carrier gas and the temperature is 0.5 Torr.
A high-frequency power with a frequency of 13.56 Mllz was applied under a back pressure of 100 ml, and a preliminary discharge was performed for 10 minutes. Then, S
A reaction gas consisting of iN4 and B2H6 was introduced, and the flow rate ratio of (Ar+SiH4) was 1:1:(1,5X10).
+ B 2H6) P+ type a-8i that plays a charge blocking function by decomposing the mixed gas by glow discharge:
The H layer 44 was formed to a predetermined thickness at a deposition rate of 6 ttm/hr. Subsequently, the flow rate ratio is 1:1:(5X 10"-'
) (Ar+SiH4+B2H6) mixed gas was subjected to discharge decomposition to form a boron-doped a-8i:H layer 43 of a predetermined thickness. As a result, the flow rate ratio is 40:3:90: (1
,5X10-5) of (Ar:SiH4:CH4:
PH,) Mixed gas at reaction pressure P = 1. OTorr
A surface protective layer 45 was further provided by glow discharge decomposition at a discharge power Rf of 400 W, and an electrophotographic photoreceptor was completed. At this time, the violet of PH3 was variously changed, and corresponding photoreceptors were obtained. In addition, CO2 was used as an oxygen source when forming the surface layer 45 with a-8iCO, and an appropriate amount was supplied as necessary. Data No. 2 was obtained by changing O children in /I64 of Table 1. (Numbers are ATM%) In an environment with an image flow temperature of 33°C and a relative humidity of 80%, the photoreceptor was placed in an electrophotographic copying machine U-Bix 2500 (manufactured by Konica Corporation → modified machine) for 24 hours, and then the developer was ,paper,
After 1000 copies were made without contact with the blade, an image was produced and the degree of image blurring was determined based on the following criteria. ○: There is no image blurring, and the reproducibility of 5.5-point alphabetic characters and thin lines is good. △: 5.5 point letters are crushed and difficult to read. X: 5.5 points of unreadable letters. Scratch Resistance In the above, photoreceptors provided with surface-modified layers with various amounts of oxygen were prepared, and the state of scratches was observed. ○: Almost no scratches. △: There are scratches. ×: Very many scratches. The results are summarized in Light-1 below. From this result, it was found that when the photoreceptors (7 papers 2 to 7) were prepared according to the present invention, electrophotographic photoreceptors with significantly less image deletion were obtained. Also, from Table 2, based on the present invention, 11 to 1
3 has excellent characteristics. Table-2

[Brief explanation of the drawing]

3 to 2 show examples of the present invention, in which FIG. 1 is a sectional view of an a-3i photoreceptor, and FIG. 2 is a schematic sectional view of a glow discharge device. In addition, in the symbols shown in the drawings, 39......a-8i system photoreceptor 41...
... Support (substrate) 43 ... Photoconductive layer 44 ... Charge blocking layer 45 ...
......Surface modified layer. Agent Patent attorney Aisaka Youngest brother Figure 1 Figure 2 Figure 62 63 64 65 bb b/
(Spontaneous) Narration and Kasu 11 Masatei July 1988 Ishiguchi 1, Indication of the case 1988 11 Patent Application No. 31304 2, Name of the invention Photoconductor 3, Relationship with the i+li positive case Patent application Address: 1-26-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Name:
(127) Konica Co., Ltd. 4, agent address: FINE Building 6, 2-4-11 Shibasaki-cho, Tachikawa-shi, Tokyo, subject of amendment

Claims (1)

[Scope of Claims] 1. A photoconductive layer made of amorphous hydrogenated and/or halogenated silicon, and a surface-modified layer deposited on the surface of the photoconductive layer; The layer is made of amorphous hydrogenated and/or halogenated silicon containing carbon atoms and oxygen atoms and also contains impurity elements of group VA of the periodic table, and the amount of oxygen atoms is 1 to 20 atm % (
However, the total amount of silicon atoms, carbon atoms, and oxygen atoms is 100 atm %. ), and the impurity element is 1 when forming the surface modified layer by glow discharge decomposition.
The photoreceptor is doped in the surface modification layer under the condition of 0^-^3 capacity ppm≦[compound of impurity element]/[silicon compound]≦10^3 capacity ppm.