JPH01289963A - Photosensitive body - Google Patents

Abstract

PURPOSE:To obtain a photosensitive body having high durability for repeated use and providing superior picture images by specifying contents of C and N of a surface modifying layer, an integrated area of an infrared absorption curve at a specified wave number, and an optical band gap of the surface modifying layer, etc. CONSTITUTION:The title photosensitive body has a surface modifying layer consisting of amorphous hydrogenated and/or halogenated silicon layer, and each content of C and N in the surface modifying layer is defined, respectively, by 30atomic%<=[C]<100atomic%, and 0atomic%<=[N]<=50atomic%, (wherein 30atomic%<[C+N]<100atomic%). An integrated area (S) of an infrared absorption curve at 1,200-1,300cm<-1> wave number of the surface modifying layer resulted by Si-CH3 is within a range expressed by the formula I, and an optical band gap of the surface modifying layer is specified to >=2.4eV. Thus, a photosensitive body causing no degradation of picture image quality and having high durability for printing is obtd.

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, amorphous silicon (
Electrophotographic photoreceptors using a-3i) as a matrix have been proposed in recent years.

Since such aSi has so-called dangling bonds, amorphous hydrogenated silicon (a-3i: H), which compensates for these defects with hydrogen atoms, increases dark resistance and improves photoconductivity. is proposed.

However, photoreceptors with a-3i:H surfaces 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 referred to as a S+C:
Regarding I (referred to as), its manufacturing method and existence are "'Ph
11. Mag.

Vol. 35'' (1978), etc., and its characteristics include high surface compatibility and surface hardness, a
-3i: High dark resistivity compared to 11 (10”~
1013 Ω-cm), and 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 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-5i:H is disclosed in, for example, JP-A-57-115559.
It is proposed in the publication No. According to this, a-5
a −5i C: on the charge generation layer consisting of i:H;
The T-I layer is formed as a surface modified layer.

However, when the 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, especially in terms of scratch resistance and image loss resistance during repeated use. It turned out that I had a sexual problem.

C1. Purpose of the Invention An object of the present invention is to provide a photoreceptor that can withstand repeated use and can produce good images.

21 Structure of the invention and its effects, that is, the present invention provides a surface modified layer made of amorphous hydrogenated and/or halogenated silicon containing at least carbon atoms and nitrogen atoms among carbon atoms, nitrogen atoms, and oxygen atoms. and the carbon content of this surface modified layer ([: C
)) and nitrogen content (1:N)) are respectively 30atomic%≦(C:l<100100at
o% Oatomic%〈[N]≦50atomic%
(However, 30atomic% < (C+N) < 10
0100aLo%. ), and the integral area (S) of the infrared absorption curve due to S+ cl+3 at wave numbers 1200 to 1300 cm for the surface modified layer is 5-JZ:2a(ω)dω≦10,000(cm -2)
[However, it is expressed as a(ω)-1-LIog1ol, and d-
i.

ω is the infrared wave number (cm-'), d is the thickness of the surface modified layer (
cm), ■(ω) is the transmitted light intensity, and Io is the incident light intensity. ), and the optical band gap of the surface-modified layer is 2.4 eV or more.

According to the present invention, the surface-modified layer not only contains at least carbon atoms, nitrogen atoms, and oxygen atoms, but also has an infrared absorption area of the surface-modified layer of the above-mentioned S By specifying ≦10.000 (cm""), satisfactory scratch resistance can be obtained, there is no deterioration in image quality due to the occurrence of white streaks, and excellent printing durability can be achieved.

In addition, the optical hunt gap (Eg, ○p) of the surface modified layer
Since t) is limited to a specific range of 2.4 eV or more,
In addition to the above, image deletion is greatly reduced, making it even more possible to achieve higher image quality.

Po, Example Hereinafter, the present invention will be described in detail with reference to examples.

FIG. 1 shows an a-5i electrophotographic photoreceptor 3 according to this embodiment.
9. This photoreceptor 39 has an a-3i charge blocking layer 44 provided as necessary on a drum-shaped conductive support substrate 41 such as Af2, and an a-5i charge blocking layer 44.
: A photoconductive layer 43 consisting of H and a-3iCN containing at least C and N of C, N and O:H or a-S
It has a structure in which a surface modified layer 45 made of iCN○nide I is laminated. The charge blocking layer 44 is a-
5i:Hla-3iC:l (or a-3iN:H), and may be doped with an element of Group 1 TIA or Group VA of the periodic table. In addition, the photoconductive layer 43 may also be doped with a similar impurity. may be doped.Photoconductive layer 43
are the resistivity ρ in the dark and the resistivity ρ1 when irradiated with light. The ratio is sufficiently large as an electrophotographic photoreceptor, and the photosensitivity (particularly to light in the visible and infrared regions) is good. Note that an intermediate layer such as a-3iC may be provided between the layers 45-43.

What should be noted here is that the surface modified layer 45 is C1N, ○
a-3iCN containing at least C and N: I
-1 or a-5i (CN○): Infrared absorption area near infrared wavenumber 1240c++r' caused by Si C1l:+ due to the inclusion of C and H as well as H (S above) 10. OOOcm-2 or less, preferably 6.000cm-2 or less, more preferably 3+
It is set within a specific range of 000 cm-2 or less.

By thus limiting the infrared absorption area near the wave number due to Si CL of the surface modified layer 45 to a specific range, the mechanical strength, especially the scratch resistance, of the surface modified layer 45 is significantly improved. It has finally become clear.

Regarding the composition of the surface modified layer 45, 30a tomic%≦(C]<100100at
o%Q atomic%〈[N1650atomic%
30atomic%< [C+N) or l: C-1-
N + 0] < 100100ato% (However, (Si) + (C) + (N) = 1001
00ato% or [:Si )+[C']+(N)+
l:○) = 100100ato%, 40atomic%≦(C)≦65atomic%L
atomic%≦(N)≦35atomic%40
Atomic%≦[: C1N) or [: C-1-
It is further desirable that N + O)≦70 atomic%. (Here, atomic% represents the percentage of the number of atoms). C1-N or C-1-N -
If the content of +-O is too small or too large, the above-mentioned effect of improving scratch resistance will be poor. In this case, [C]
If it is less than 30 atomic%, scratch resistance will be improved.
Further, the inclusion of [N] prevents image blurring, but unless the upper limit is set to 50 atomic%, the scratch resistance will be poor.

In order to improve the charging ability of the surface modified layer 45, for example, CBzH6]/[5il14] is used in the glow discharge method described below.
-10-3~]04 volume ppm, preferably 10-'
~102 capacitance ppm of Group IIA elements of the periodic table, or [:PII3)/[5i114]-10-3~10'
Capacity ppm, preferably 10-1 to 102 p.p.m.
It is preferable to dope with a group VA element of the periodic table of p m.

These Group IIA elements and Group VA elements of the periodic table may be contained together in the surface modification layer.

The thickness of the surface modified layer 45 is 200 to 30,000 mm.
It is desirable to set it as 1,000~1o,oooA
It is even more desirable that If the film thickness is too large, the residual potential (1) becomes too high and the photosensitivity decreases, resulting in a-3
It is easy to lose the good characteristics of i-type bad sensitivity.

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 may be composed of a-5i:I (with a composition of 5 to 40 at.
It is best to set it as omic%, and when it contains a halogen instead of or in combination with ``■'', the halogen is 5 to 40ato.
mic%, or the total amount of H and halogen is 5 to 40a
It is preferable to set it as tomic%. This photoconductive layer 43 contains impurities, particularly Group 1A of the periodic table or VA.
It is preferable to dope a group element. For example, during glow discharge (described later), (Bzl16]/(SiH4) -10-3~
100 (preferably 10'' to 10) capacity ppm, [p
n:+)/(Sil14) -10- to 100 (preferably 10-2 to 10) p p m.

Further, the thickness of this layer 43 is preferably 5 to 100 μm, preferably 10 to 30 μm. If the thickness of the photoconductive layer 43 is too small, a sufficient charging potential cannot be obtained, and if it is too large, the residual potential increases, which is insufficient for practical use.

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 111A of the periodic table (for example, boron) by glow discharge decomposition. , becomes P type (and further P type).

It is desirable to control the doping amount as follows depending on the composition of the blocking layer.

a-3i:H (H content 5-40 atomic%): [
BzH6) / (Silla) -10-3 ~ IO' capacity ippm (furthermore 10-1 ~ 102 capacity ppm) (P
H:+)/(SiH4]-10-3~10' Capacity pp
m (furthermore, 10-1 to 102 capacity ppm) a-5iC
: H (H content % 5-55-50 ato%, C content 5-100 aLomic%): 1:Bz116:]/C3il14:] -10-3~
106 capacity ppm (furthermore 10-1 to 104 capacity ppm
)CPH3)/[5il14) -10'' to 106 volume ppm (further 10-1 to 104 volume ppm) a-
5iN:H (N content 5-55-50 atomic%, N content 5-60 atomic%); [Bz116]/[5i114]-10-3 to 10' volume ppm (furthermore 10-1 to 104 volume ppm) [P
H3]/[SiH4]-10-3~106 volume ippm (
Further, the blocking layer 44 preferably has a thickness of 100 to 2 μm. If the thickness is too small, the blocking effect will be weak, and if it is too thick, 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 boron, the impurities to be doped include A
j2. Periodic table 1 of Ga, In, T42, etc.
Group 11A elements can be used, and in addition to phosphorus, As
, sb, and other Group VA elements of the periodic table 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.

Inside the vacuum chamber 52 of this device 51, a drum-shaped substrate 41
is set so as to be vertically rotatable, and the substrate 4 is heated by a heater 55.
1 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,
In the figure, 62 is a source of 5tH4 or gaseous silicon compound, 63 is a source of hydrocarbon gas such as CH4, and 64 is N
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 (for example, B2116) supply source, 68
is each flowmeter. In this glow discharge device, first, after cleaning the surface of the support, for example, the Aρ substrate 41, it is placed in a vacuum chamber 52, and the gas pressure in the vacuum chamber 52 is set to 1.
The temperature is adjusted to 0-6Toor and the temperature is evacuated, and the substrate 41 is heated and maintained at a predetermined temperature, particularly 100 to 350°C (preferably 150 to 300°C). Then, using high purity inert gas or B2 as a carrier gas, 5iHa
or gaseous silicon compounds, CH4, N2, NH3, C
O2.0° or the like is appropriately introduced into the vacuum chamber 52, for example, 0.0°.
A high frequency voltage (for example, 13.56 MB2) is applied by the high frequency power supply 56 under a reaction pressure of 0.01 to 10 Torr. As a result, each of the above-mentioned reaction gases is decomposed by glow discharge between the electrode 57 and the substrate 41, resulting in a -5i C: H, a -
3i:H,a-5iCN:Hl in the above layer 44.
43.45 on the substrate (i.e., e.g. the first
(corresponding to the example in the figure).

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 it is possible to improve the film quality (especially electrical properties) of the photoreceptor. can.

In addition, when forming the above a-3i photoreceptor photosensitive layer,
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 −3i :F ,,
a-3t: H: F, a-3iN
: F X a -5iN :H:F, a-
5iC:F,,a 5ick)INF, etc. may also be used.

The above manufacturing method is based on the glow discharge decomposition method, but there are also sputtering methods, ion blating methods, and methods in which Si is evaporated 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.

Drum-shaped AI is produced using glow discharge decomposition method! An electrophotographic photoreceptor having the structure shown in FIG. 1 was prepared on a support.

That is, first, the support, for example, a smooth surface, is adjusted to have a gas pressure of 10'' Torr and evacuated.
Further, the substrate 41 is heated and maintained at a predetermined temperature, particularly 100 to 350°C (preferably 150 to 300°C). Next, high-purity Ar gas is introduced as a carrier gas, and 0.
High frequency power with a frequency of 13.56 MH2 was applied under a back pressure of 5 Torr, and preliminary discharge was performed for 10 minutes. Next, a reaction gas consisting of SiH4 and B2Hb was introduced, and the flow rate was 1:1:(1,5X10-3).
A P' type a-3i:H layer 44 having a charge bronking function was formed to a predetermined thickness at a deposition rate of 6 μm/hr by glow discharge decomposition of a mixed gas (Ar+SiH4+B2H6). Subsequently, the flow rate ratio is 1:1:(5X10-
') (Ar+5il(4+BzH6) mixed gas was subjected to discharge decomposition to form a boron-doped A-5ill (layer 43) with a predetermined thickness.Subsequently, the supply of impurity gas was stopped,
(Ar:SiH4:C1-1,
) The mixed gas was decomposed by glow discharge at a reaction pressure P = 0.5 Torr and a discharge power Rf = 400 W to form an intermediate layer of a predetermined thickness, and further, a (A
r: Si H4: CH4: N H3) mixed gas at reaction pressure P-Q, 5 Torr, discharge power Rf = 400
A surface protective layer 45 was further provided by glow discharge decomposition using w to complete an electrophotographic photoreceptor.

Note that when the surface layer 45 was made of a-3iCN◯, CO2 was used as the oxygen source.

In addition, in order to control the composition ratio, the gas flow rate ratio,
The reaction pressure and discharge power were set appropriately.

Next, various tests were conducted using each of the photoreceptors described above as follows.

Using a modified electrophotographic copying machine [1-Bix 2500 (manufactured by Konica Corporation)], a jam test was conducted in the following steps.

■ Set the separation current to zero and force a jam.

■ Fujiwash for 30 seconds in a jammed state.

■ Repeat ■ and ■ 30 times.

■ Determine the presence or absence of jam damage by displaying the image.

○ No jamming scratches △ Several jamming scratches × Many jamming scratches The photoreceptor was modified into an electrophotographic copying machine U-Bix 2500 (manufactured by Konica Corporation) under an environment of 100 plates vagina temperature of 33°C and relative humidity of 80%. After acclimatizing in the machine for 24 hours, after making 1000 copies without contacting the developer, paper, or blade,
Images were captured 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.

〇2 5.5 point English letters are slightly thick.

△: 5.5 point English letters are blurred and difficult to read.

X: 5.5 points of unreadable letters.

The results are summarized in Table 1 below. These results show that if the photoreceptors (Nos. 2 to 7) are prepared according to the present invention, photoreceptors particularly excellent in scratch resistance for use in electrophotography can be obtained.

Table-1 I Si 1-・To 1・Giant *Wave number 1240c caused by the Si CI+3 mentioned above
Infrared absorption area S near m-' The infrared absorption area S of each photoreceptor No. 1 to 9 above is actually determined by applying the film material of each surface modification layer onto a Si wafer using the method described above. The infrared absorption spectra of each obtained sample were measured using an infrared spectrometer, and calculations were made from the infrared absorption spectra.

In addition, in the above method, it was found that the infrared absorption intensity of 5i-CH3 was lowered by lowering the reaction pressure. Further, the ratio of the dark resistance (ρ, ) of the photoreceptor to the resistance during light irradiation (ρ+−): ρL/ρ. becomes 1 when the reaction pressure is increased.
．． When the reaction pressure is increased, S and D in the membrane approach 0.
, (spin density - density of dangling bonds) was also found to increase.

Next, using the apparatus shown in Fig. 2, S+ -
It has also been found that the absorption area S due to CHa changes and the optical energy gap (Eg, opt) also changes. To explain this below, first, the influence of CH and flow rate was measured under the following conditions and is shown in Table 2 below.

■ 5IH4-15S [CM, NH3=IS [CMAr
= 200 S[C:M Rf=400W P = 0.5 Torr Table 2 *Reaction pressure is 0.75 Torr Further, control by reaction pressure is shown below.

Condition S+H4=15 S[CM, NH,=IS[CM
CH4 = 450 S [CM Ar = 200 S [CM Rf = 400 W Table-3 In addition, in the above, the Eg and opt of the surface modified layer can be set variously by controlling the reaction conditions; It was found that this greatly affects the properties of the film, especially the image blur. This is shown in Figure 3, where Eg
, opt is set to 2.4 eV or more according to the present invention, it has been found that image deletion is rapidly reduced. That is, the above S is 100100O0' or less, and Eg and opt are 2.
．． By setting the voltage to 4 eV or higher, not only the scratch resistance but also the image blurring can be improved, and both of these characteristics can be satisfied at the same time. In the present invention, the above Eg and opt are preferably set to 2.6 eV or more,
2.7 eV or more is an extremely satisfactory range.

However, the E obtained from the conditions shown in Table 2 above in Figure 4
g, shows the relationship between opt and S.

[Brief explanation of the drawing]

1 to 4 show examples of the present invention, in which FIG. 1 is a sectional view of an a-3i photoreceptor, FIG. 2 is a schematic sectional view of a glow discharge device, and FIG. 3 is a sectional view of a glow discharge device. FIG. 4 is a graph showing the relationship between the optical band gap and the infrared absorption area. In addition, in the symbols shown in the drawings, 39...a-3i type photoreceptor 41...
... Support (substrate) 43 ... Photoconductive layer 44 ... Charge blocking layer 45 ...
......Surface modified layer. Agent Patent Attorney Hiroshi Renkan

Claims (1)

[Scope of Claims] 1. A surface modified layer made of amorphous hydrogenated and/or halogenated silicon containing at least carbon atoms, nitrogen atoms, and oxygen atoms, and this surface modification The carbon content ([C]) and nitrogen content ([N]) of the layer are respectively 30 atomic% ≦[C]<100 atomic%
0 atomic%<[N]≦50atomic% (however, 30atomic%<[C+N]<100at
Let it be omic%. ), and the wave number of the infrared absorption curve due to Si-CH_3 for the surface modified layer is 1200 to 1300 cm^-^
The integral area (S) at 1 is ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [However, a(ω)=-1/dlog_1_0I(ω)/
It is expressed as I_0, ω is the infrared wave number (cm^-^1), d is the thickness of the surface modified layer (cm), I(ω) is the transmitted light intensity, I
_0 is the incident light intensity. ] A photoreceptor in which the surface-modified layer has an optical band gap of 2.4 eV or more.