JPS6228758A - Photosensitive body - Google Patents

Abstract

PURPOSE:To improve the mechanical and the optical properties and the stability of the titled body by laminating the prescribed layers composed of such as a specific amorphous hydrogenated silicon (a-Si:H) etc. respectively. CONSTITUTION:An electric charge blocking layer 44 composed of a-Si:H contg. at least one kind atom selected from a carbon, a nitrogen, and an oxygen atoms, and heavily dopped with the group IIIa element of the periodic table, an electric charge transfer layer 42 composed of a-Si:H contg. the nitrogen atom and an electric charge generating layer 43 composed of a-Si:H are laminated on a substrate 41. And the intermediate layer 46 composed of a-Si:H contg. at least one kind atom selected from the carbon, the nitrogen and the oxygen atoms and dopped with the group IIIa or Va element of the periodic table, and the surface reforming layer 45 composed of a-Si:H contg. large amounts of the atom are laminated on the substrate 41 to form the photosensitive body 39. By providing the layers 45 and 46, the mechanical strength of the titled body becomes large. The adhesive property, the anti-fatigue property against a light and the anti-chemical stability of the layers 45 and 43 are improve. The effects as prescribed above are obtd. by merely using a fluorinated silicon or by jointly using the fluorinated silicon and the prescribed silicon.

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, 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 (a-3i) as a matrix have been proposed in recent years. a-3i has a so-called dangling bond in which the bond of 5i-3i 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, we replaced the above defects with hydrogen atoms (
The dangling bonds are filled by bonding H to Si by compensating with H). Such amorphous hydrogenated silicon (hereinafter referred to as a-3
It is called i:H. ) has a resistivity in the dark of 106 to 10
9Ω-Cffl, which is about 1/10,000 times lower than amorphous Se. Therefore, a photoreceptor consisting of a single layer of a-3i:H has the problem of a fast dark decay rate of surface potential (low initial charging potential). When irradiated with light of 3
An electrophotographic copying machine incorporating an i-series irradiance 9 is shown. According to this copying machine, a glass document mounting table 3 on which a document 2 is placed and a platen cover 4 that covers the document 2 are disposed in the upper part of a cabinet 1. Below the document table 3, an optical scanning table consisting of a light source 5 and a first mirror unit 7 equipped with a first reflection mirror 6 is provided so as to be movable in a straight line in the left and right direction of the drawing. A second mirror unit 20 for keeping the optical path length constant is connected to the first mirror unit 20.
The mirror unit moves according to the speed of the mirror unit, and the reflected light from the document table 3 side is incident on the photosensitive drum 9 as an image carrier through the lens 21 and the reflection mirror 8 in the form of a slit. . A corona charger 1 is installed around the drum 9.
0, a developing device 11, a transfer section 12, a separation section 13, and a cleaning section 14 are arranged, and the copy paper 18 fed from the paper feed box 15 through the paper feed rollers 16 and 17 is transferred with the toner image on the drum 9. Afterwards, the image is further fixed in the fixing unit 19 and then discharged onto the tray 35. In the fixing section 19, a heater 22
A fixing operation is performed by passing the developed copy paper between a heating roller 23 having a built-in image and a pressure roller 24. However, photoreceptors with a-3t: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, 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-3iC:H
It is called. ), its manufacturing method and existence are
, Mag, Vol. 35” (1978
), etc., and its characteristics include high heat resistance and surface hardness, high dark resistivity (10'2 to 10 IffΩ) compared to a-3i:H, and carbon content. The optical energy gap is 1.6~2.8e.
It is known that V varies over a range of V. However, there is a drawback that the long wavelength sensitivity becomes poor due to the widening of the band gap due to the inclusion of carbon. An electrophotographic photoreceptor combining such a-3iC:H and a-3i:H has been proposed, for example, in Japanese Patent Application Laid-Open No. 127083/1983. According to this, a-3t:H
The layer is a charge generation (photoconductive) layer, and below this charge generation layer is a
-3iC:H5 is provided, the upper layer a-3i:H provides photosensitivity in a wide wavelength range, and the lower layer a-3iC:H forming a heterojunction with the a-3i:H layer has a charged potential. We are working to improve this. However, the dark decay of the a-3i:H layer cannot be sufficiently prevented, and the charging potential is still insufficient to be practical.
The presence of HN causes poor chemical stability, mechanical strength, heat resistance, etc. On the other hand, JP-A-57-17952 discloses a-3t:
A first a-3iC:H layer is formed as an intermediate layer on the charge generation layer made of H, and a second a-3iC:H layer is formed on the back surface (support electrode side).
-3iC: Forms an H layer. In addition, as related to this known technology,
As seen in Japanese Patent No. 23543, a gradient layer (a-31t-x Cx:H) is provided between the charge generation layer and the first and second a-3iC:H layers, and the gradient layer In a-3i:H side, set as X-0, a-3iC
: A photoreceptor in which X=0.5 on the H layer side is known. However, when the present inventor conducted a study on the above-mentioned known photoreceptor, it was found that the effect of providing the intermediate layer is not so great, especially in continuous repeated use. In other words, during continuous running of 200,000 to 300,000 times, the a-3iC layer on the surface is mechanically damaged after about 70,000 to 80,000 times, and this causes white streaks and white spots as image defects, resulting in poor printing durability. is not enough. Moreover, light resistance fatigue occurs during repeated use, image blurring occurs, and electrical and optical characteristics are not always stable, and the usage environment (temperature, humidity)
The impact of this cannot be ignored. It is also necessary to further improve the adhesion between the intermediate layer and the charge generation layer. C.9 Purpose of the Invention The purpose of the present invention is to provide excellent adhesion between the intermediate layer and the charge generation layer, resistance to mechanical damage, and excellent rigidity resistance, as well as stable image quality without image deletion. It is an object of the present invention to provide a photoreceptor which has little optical fatigue during repeated use, has a low residual potential, and whose characteristics are stable regardless of the usage environment (temperature, humidity). two. The constitution of the invention and its effects, that is, the present invention provides an amorphous hydrogenated and/or fluorinated amorphous material which is heavily doped with an element of group 1I [a of the periodic table and contains at least one of a carbon atom, a nitrogen atom, and an oxygen atom. a charge blocking layer made of silicon; a charge generation layer made of amorphized silicon containing nitrogen atoms; at least; an intermediate layer made of amorphous hydrogenated and/or fluorinated silicon; and an amorphous hydrogenated and/or fluorinated silicon containing more at least one of carbon atoms, nitrogen atoms, and oxygen atoms than the intermediate layer; This relates to a photoreceptor in which an intermediate layer consisting of the following is sequentially laminated. According to the present invention, since the intermediate layer contains at least one atom of carbon, nitrogen, and oxygen, it is resistant to mechanical damage, does not deteriorate image quality due to white streaks, etc., and has high rigidity resistance. It will be excellent. Furthermore, in the present invention, since the impurity-doped intermediate layer is provided between the intermediate layer and the charge generation layer, the adhesion between the intermediate layer and the charge generation layer is improved. In addition, since the intermediate layer and intermediate layer are provided on the charge generation layer, in addition to the above, it has excellent resistance to light fatigue during repeated use, has no image fading, has low residual potential, and has electrical and optical properties. It has been confirmed that the characteristics are always stable and are not affected by the usage environment. E. Examples Hereinafter, the present invention will be explained in detail with reference to examples. FIG. 1 shows an a-3i electrophotographic photoreceptor 39 for positive charging according to this embodiment. This photoreceptor 39 is A1
A-5i:H (a-S i (C)(N)(0):H), and an a- type charge blocking layer 44 consisting of a P+ type charge blocking layer 44 consisting of a group M element (e.g. boron) of the periodic table and an a- 8i:) ((This is a-3
It is expressed as iN:H. ), a charge transport layer 42 consisting of a-
3i: A charge generation layer made of H (without impurity doping or made intrinsic) 43 and a Pf type or N+ type heavily doped with Group Ia or Group Va elements of the periodic table, C, N, an intermediate layer 46 made of amorphous hydrogenated silicon containing at least one of
Amorphous hydrogenated silicon doped with a group A or group Va element to make it P-type, N-type, or intrinsic (or without impurity doping) and containing at least one of N, C, and O (this is called a-3i (C) (N) (
0) : Represented as H. ) and a layered intermediate layer 45. The charge generation layer 43 has a ratio of resistivity .rho. in the dark to resistivity .rho.1 during light irradiation that is sufficiently large for an electrophotographic photoreceptor, and has good light intensity (particularly against light in the visible and infrared regions). In addition, when the carbon atom content of each of the above layers is in the range of 0 to 70%, the optical energy gap (
Since there is an almost linear relationship with E g, opt),
It can be defined by replacing the carbon atom content with the optical energy gap. In addition, if the carbon atom content of a-5iC:H is appropriately selected, remarkable effects such as an increase in specific resistance and an improvement in charging potential holding ability can be obtained as shown by curve a in FIG. 3. That is, as shown by curve a in FIG. 3, when the carbon atom content is 30
When ~90% a-3iC:H is used, the resistivity varies with carbon content and is greater than 10'2 ohm-cm. The above tendency is that a-S containing N or O instead of carbon
The same applies to iN: Hla-3iO:H. The above layer 45 is essential for modifying the surface of the photoreceptor and making the a-3i photoreceptor practically superior. In other words, it enables the basic operations of an electrophotographic photoreceptor: charge retention on the surface and attenuation of the surface potential due to light irradiation. Therefore, the repetitive characteristics of charging and optical attenuation become 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. Further, since the layer 45 has a high surface hardness, the development 1. transcription,
It has abrasion resistance in processes such as cleaning, and also has good heat resistance, so processes that apply heat such as adhesive transfer can be applied.In order to achieve the above-mentioned excellent effects overall, , it is important to choose the composition of layer 45. That is, when containing carbon atoms, Si+C=100at
When omic% (hereinafter, atomic% is simply expressed as %), 1%≦(C)590%, furthermore 10%≦[
03570% is desirable. Due to this C content, the above-mentioned resistivity becomes the desired value, and the optical energy gap becomes approximately 2.5 eV or more, and the irradiated light is a-3i due to the so-called optically transparent window effect for visible and infrared light. : It becomes easier to reach the 8th layer (charge generation layer) 43. However, if the C content is 1% or less, disadvantages such as mechanical damage occur, and the specific resistance tends to fall below the desired value.
In addition, a portion of the light is absorbed by the surface layer 45, and the photosensitivity of the photoreceptor tends to decrease. In addition, if the C content exceeds 90%, the amount of carbon in the layer increases, and semiconductor properties are likely to be lost, and the deposition rate when forming the a-3iC:H film by the glow discharge method is likely to decrease. The amount of C content is preferably 90% or less. Similarly, in the case of layer 45 containing nitrogen or oxygen, 1%≦
[N9590%, (furthermore 10%≦(N)570%) is good, 0%

[0]≦70% (furthermore, 5%≦[0953
0%) is better. In order to improve the charging ability, the intermediate layer 45 may have a high resistance. For this purpose, the intermediate layer may be made intrinsic. In order to facilitate the injection of electrons or holes from the intermediate layer into the intermediate layer and to minimize the residual potential in the use of positive or negative charging, the intermediate layer may be of P or N type. The amount of impurity doped in each case (at the time of glow discharge decomposition described later) may be as follows. Intrinsicization: Bz Hb / Si H42~50 Visual capacity mP type: B2 H6 / SiHa 50~
1000”N type: PH:I/S iHa
1~1000'' Also, the layer 45 is a-3iC
It is also important to select the film thickness within the range of 400≦L≦5000 (particularly 400≦t<2000). That is, if the film thickness exceeds 5000, the residual potential v7 becomes too high and the photosensitivity decreases, resulting in a-3
It is easy to lose the good characteristics as an i-type photoreceptor. Furthermore, if the film thickness is less than 400, charges will not be charged on the surface due to the tunnel effect, resulting in an increase in dark decay and a decrease in photosensitivity. The intermediate layer 46 is provided to improve sensitivity, reduce residual potential, improve adhesion of the intermediate layer, and stabilize images. In order to improve the above characteristics, it is necessary to make it P or N type. The impurity doping amount is (P Hi )/C3i Ha
) = 1-1000 (preferably 10-500) volume l
ppm. CBz Hb )/(S i H4)=10~100
0 (preferably 50 to 500) ppm. The C, N, and C contents of the intermediate layer 46 are O<[C]≦10%, O<[:N]≦10%, 0<(0
)≦5%. The thickness of this intermediate layer is preferably 50 to 5,000 people, but if it exceeds 5,000 people, the same phenomenon as described above is likely to occur, and if it is less than 50 people, the effect as an intermediate layer will be poor. Regarding the charge generation layer 43, in order to improve the charging ability,
The resistance of the charge generation layer may be increased. For this purpose, the charge generation layer may be made intrinsic. This intrinsicization requires BZ
It is preferable that Hb/S i H4 = 1 to 20 ppm by volume. Further, the charge generation layer has a thickness of 1 to 10 μm, preferably 5 to 7 μm.
It is preferable to set it to μm. If the thickness of the charge generation layer 43 is less than 1 μm, the photosensitivity will not be sufficient, and if it exceeds 10 μm, the residual potential will increase, which is insufficient for practical use. Regarding the charge transport layer 42, it is necessary to make it intrinsic in order to optimize charging ability and sensitivity. The doping amount for making it intrinsic is (Bz Hb) / (S iH4) = 1 to 2
000 volume ft p p m is optimal. However, since the above value depends on Nff and degree, it is not necessarily limited to the above value. The thickness of the charge transport layer is 10 to 30 μm
It is better to The composition of the charge transport layer is preferably 1%<[N3530%, preferably 10%≦(N)530%. Further, in order to sufficiently prevent electron injection from the substrate 41 and improve sensitivity and charging ability, the charge blocking layer 44 is doped with an element of Group Ma of the periodic table (for example, boron) by glow discharge decomposition. , becomes P type (and further p+ type). Doping stars are controlled by the composition of the blocking layer as follows. a-5iC or a-3iCO: P type (P“); B2 H6/S i H420~
5000 capacity ppm a-3iN or a-3iNO: P type (P+); Bz Hb / Si HalO
OO~5000vol Ltppm The blocking layer may be a compound such as 5iO1sioz. Further, the blocking N44 preferably has a film thickness of 500 to 2 μm. If it is less than 500, the blocking effect will be weak, and if it exceeds 2 μm, the charge transport ability will be poor (easily). Regarding the composition of blocking N44, it is desirable to have the following composition: 1% <[03590%; Preferably 10%≦(C)570%, less than 1% [N] 59
0%, preferably 10% [N] 570%, 0
%≦(0)570%, preferably O%≦

[0]≦30%
It is better to Note that each of the above layers needs to contain hydrogen. In particular, the hydrogen content in the charge generation layer 43 is essential for compensating for dangling bonds and improving photoconductivity and charge retention, and is preferably 10 to 30%. This content range also applies to the intermediate layer 45, blocking layer 44, and charge transport layer 42. Also, as an impurity for controlling the conductivity type, in addition to boron, A7! , Ga, In, Tj2, etc. Periodic Table 11
Group 1a elements can be used. In addition to phosphorus, Group Va elements of the periodic table, such as As and sb, can be used for N-type formation. Next, a method for manufacturing the above-mentioned photoreceptor (for example, drum-shaped) and its apparatus (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 a gaseous silicon compound, 63 is a supply source of hydrocarbon gas such as CH4, and 64 is a supply source of N2.
65 is a supply source of oxygen compound gas such as 02, 66 is a carrier gas supply source such as Ar,
67 is an impurity gas (e.g. Bz Hb) supply source, 68
is each flowmeter. In this glow discharge device, first, the surface of a support, for example, an Aβ substrate 41, is cleaned, and then placed in a vacuum chamber 52, and the gas pressure in the vacuum chamber 52 is set to 1O.
The temperature is adjusted to -6 Torr and the air is evacuated, and the substrate 41 is heated and maintained at a predetermined temperature, particularly 100 to 350°C (preferably 150 to 300°C). Next, using a high-purity inert gas as a carrier gas, SiH4 or a gaseous silicon compound, CH4, N2.02, etc. are appropriately introduced into the vacuum chamber 52, and the high-frequency power source 56 is used under a reaction pressure of, for example, 0.01 to 10 Torr. High frequency voltage (for example 13.
Apply 56 Ml(z). As a result, each of the above reaction gases is decomposed by glow discharge between the electrode 57 and the substrate 41, resulting in P-type a-5iC:H and i-type a-3iN:H. a-3i: HXP+ or N+ type a-3iCO: Ha-3
iCO:H is deposited as layers 44, 42, 43, 46, 45 as described above on the substrate in succession (ie 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-3i layer on the support, so the film quality (especially electrical properties) of the photoreceptor can be improved. . In addition, when forming the above a-3i photoreceptor photosensitive layer,
In order to compensate for dangling bonds), the above H
Instead, or in combination with H, fluorine is introduced in the form of SiF4, etc., and a-3i:F, a-3i:H:F, a-
3iN:F. a-3iN:H:F, a-3iC:F. It can also be a-3iC:H:F. In this case, the amount of fluorine is preferably 0.5 to 10%. The above manufacturing method is based on the glow discharge decomposition method, but other methods include the sputtering method, the ion blating method, and the method of evaporating Si while introducing activated or ionized hydrogen in a hydrogen discharge tube. (In particular, Japanese Patent Application Laid-Open No. 56-78413 (Patent Application No. 54-152) filed by the present applicant)
The above photoreceptor can also be manufactured by the method of No. 455). Hereinafter, the present invention will be described with reference to specific examples. By glow discharge decomposition method, the first
An electrophotographic photoreceptor having the structure shown in the figure was manufactured. That is, first, after cleaning the surface of a support, for example, a drum-shaped Aβ substrate 41 having 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 to 350°C).
Heat and maintain at 300°C. Next, high-purity Ar gas was introduced as a carrier gas, and high-frequency power with a frequency of 13.56 MHz was applied under a back pressure of Q, 5 Torr to perform a preliminary discharge for 10 minutes. Next, a reaction gas consisting of SiH and B2H6 was introduced, and the flow rate ratio was 1:1:1:(1,5xlO-
') (7) (A r + S i, H4 + CH4
or Nz +Bz Hb) By glow discharge decomposition of the mixed gas, P-type a which plays a charge blocking function
-S i C: The I-1 layer 44 and the a-3J:l charge transport 142 were sequentially formed to a predetermined thickness at a deposition rate of 6 pm/hr. Subsequently, the supply of B2H and CH was stopped, and SiH4 was decomposed by discharge to form an a-3i:H layer 43 with a thickness of 5 μm. Subsequently, the intermediate layer 46 is formed by glow discharge decomposition by changing the flow rate ratio of impurity gas and by changing the film thickness.
was formed, and an a-3iCO:H or a-3iNO:H surface protective layer 45 was further provided to complete an electrophotographic photoreceptor. As a comparative example, a photoreceptor without an intermediate layer was created. The structure of the photoreceptor thus produced was summarized as follows. (1) 8 intermediate layer: a-3iNO2H or a-3iCO:H' (2), intermediate layer: doping amount, film thickness change (see Figure 5) (31, a-3i: H charge generation layer: Film thickness = 5 μm (41, a-3iN:H charge transport N: Film thickness = 15 μm N content = 12% With di-B doping for positive charging (5), a-3ic: H or a-3iN:H charge blocking Layer: Film thickness = 1 μm Carbon content = 12% (6) Support: Al cylinder (mirror polished finish) Next, various tests were conducted using each of the above photoreceptors as follows. As shown in Figure 6, the 0,
A load W is applied to the 3R diamond needle 70, and the photoreceptor is moved by the motor 71.
Rotate it with and scratch it. Next, the electrophotographic copying machine U-
B 1x1600 (manufactured by Konishiroku Photo Industry Co., Ltd.) An image is produced using a modified machine, and the scratch strength (g) of the photoreceptor is determined by the load at which white streaks appear on the image. After acclimatizing the photoconductor in a modified electrophotographic copying machine U-B 1x4500 (manufactured by Konishiroku Photo Industry Co., Ltd.) for 24 hours in an environment with a temperature of 33°C and a relative humidity of 80%, the developer and paper were removed. ,
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 at all, and the reproducibility of 5.5-point alphabetic characters and thin lines is good. ○: 5.5 point alphabetic characters are slightly thicker. △: 5.5 point letters are crushed and difficult to read. X: 5.5 point English letters are illegible. Imperial V, I (V) U - B 4 by measuring the potential using a 1x2500 modified machine.
Static elimination light with a peak at 00 nm 30 j! ux-se
The surface potential of the photoreceptor that remains after irradiation with c. Charged potential■. (V) Surface potential immediately before development measured using a U-B 1x2500 modified machine (manufactured by Konishi Roku Photo Industry Al) with a 360SX type electrometer (manufactured by Toresok Co., Ltd.) under conditions of a photoreceptor inflow current of 200 μA and no exposure. Half-reduced exposure +yz (,1ux-sec) Using the above device, the long wavelength component of 620 nm or more of the image exposure wavelength was sharply cut using a dichroic mirror (manufactured by Genshu Kogaku Co., Ltd.), and the surface potential was changed from 500 V to 250 V. ■The amount of exposure required to reduce the amount of light by half. (The exposure amount was measured using a 550-1 light meter (manufactured by EGandG)) The results are summarized in FIG. 7. These results show that if a photoreceptor is prepared according to the present invention, a photoreceptor with excellent performance for electrophotography can be obtained.

[Brief explanation of drawings]

1 to 7 show embodiments of the present invention, FIG. 1 is a two-sectional view of an a-3t photoreceptor, and FIG. 2 is an a-3 sectional view.
Graph showing the optical energy gap of iC, FIG. 3 is a graph showing a-3iCO resistivity, FIG. 4 is a schematic cross-sectional view of the glow discharge device, FIG. 5 is a table showing the layer structure of each photoreceptor, FIG. 6 is a schematic diagram of a scratch strength tester, and FIG. 7 is a table showing the characteristics of each photoreceptor. FIG. 8 is a schematic sectional view of a conventional electrophotographic copying machine. In addition, in the symbols shown in the drawings, 39...a-3i photoreceptor 41...support (substrate) 42...charge transport layer 43...charge generation layer 44... ... Charge blocking layer 45 ... Intermediate layer 46 ... Intermediate layer. Agent Patent Attorney Hiroshi AisakaFigure 2a-9i-xCx:HxFigure 3Figure 6Figure 4

Claims (1)

[Claims] 1. A charge blocking layer made of amorphous hydrogenated and/or fluorinated silicon heavily doped with a Group IIIa element of the periodic table and containing at least one of carbon atoms, nitrogen atoms, and oxygen atoms; A charge transport layer made of amorphous hydrogenated and/or fluorinated silicon; A charge generation layer made of amorphous hydrogenated and/or fluorinated silicon; Doped with a group IIIa or Va element of the periodic table and made of carbon atoms, nitrogen an intermediate layer made of amorphous hydrogenated and/or fluorinated silicon containing at least one of atoms and oxygen atoms; containing at least one of carbon atoms, nitrogen atoms and oxygen atoms in a larger amount than the intermediate layer; A photoreceptor in which surface-modified layers made of amorphous hydrogenated and/or fluorinated silicon are sequentially laminated.