JPH01185641A - Photosensitive body - Google Patents

Abstract

PURPOSE:To make possible to maintain the good image of the title body even at the time of repetitive use the body by constituting a surface reforming layer of a hydrogenated and/or a halogenated amorphous silicone which contains carbon atom and has the specified range of the integrated area in the specified wave number of an infra-red absorption curve. CONSTITUTION:The photosensitive body 39 is formed by laminating an electric charge blocking layer 44 composed of a-Si, a photoconductive layer 43 composed of a-Si:H and the surface reforming layer 45 composed of the hydrogenated amorphous silicone contg. carbon and oxygen atoms and at least one of the carbon atom, on a drum shaped conductive supporting substrate 41 composed of Al etc. As the layer 43 has sufficiently a large ratio of the specific resistivity at a dark place to that at a light place, the photosensitivity of the body at a visible and an infra-red regions is improved. As the layer 45 is defined the infra-red absorption area at a wave number of 1,200-1,300cm<-1> resulting from Si-CH3 contg. carbon and hydrogen atoms, to the range shown by formula I, the mechanical strength, especially the scratch resisting property of the photosensitive body are remarkably 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, amorphous silicon (
Electrophotographic photoreceptors using a-3i) as a matrix have been proposed in recent years.

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

However, photoreceptors with a-Si: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 referred to as a-3iC:
It is called H. ), its manufacturing method and existence are “Ph11
．． Mag, Vol. 35'' (1978), etc., and its characteristics include high heat resistance and surface hardness, and high dark resistivity (10
2 to 10 Ω-cm), and that the optical energy gear varies 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-3i;H has been proposed, for example, in Japanese Patent Application Laid-Open No. 115559/1983. According to this, a-3i:)
(A-5IC:8 layer is formed as a surface modification layer on the charge generation layer consisting of (A-5IC:8 layer).

However, when the present inventor investigated the above-mentioned known photoreceptor, it was found that even if a surface modification layer is provided, it is still not as effective as expected, and there are problems in particular with respect to scratch resistance during repeated use. It has been found.

The object of the present invention is to provide a photoreceptor capable of obtaining an image.

29 Structure and effect of the invention, that is, the present invention has a surface modified layer made of amorphous hydrogenated and/or halogenated silicon containing at least carbon atoms and oxygen atoms, The wave number of the infrared absorption curve measured for the quality layer is 1200~
The integral area (S) at 1300c'1 is S=f'''a (ω)dω≦10,000 (c'2)
where ω is the infrared wave number (am-”), d is the thickness of the surface modified layer (cm), I (ω) is the transmitted light intensity, and I
O is the incident light intensity. ] This relates to a photoreceptor within the range shown below.

According to the present invention, the surface modified layer only contains at least carbon atoms and oxygen atoms (and the infrared absorption area of this surface modified layer is set to S≦10,000 as described above).
(cm-2), satisfactory scratch resistance can be obtained for the first time, there is no deterioration in image quality due to the occurrence of white streaks, and the printing durability is excellent.

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

FIG. 1 shows an a-3i electrophotographic photoreceptor 3 according to this embodiment.
9. This photoreceptor 39 is provided on a drum-shaped conductive support substrate 41 such as A1, if necessary.
It has a structure in which a -3i-based charge blocking layer 44 and a surface modification layer 45 made of a-3i:H photoconductive layer s1c(o):u) are laminated. The charge blocking layer 44 may be composed of a-3i:H, a-3iC:H or a-SiN:H, and may be doped with elements of group 111A or VA of the periodic table. Further, the photoconductive layer 43 may also be doped with similar impurities. The photoconductive layer 43 has a ratio of resistivity ρD in the dark to resistivity ρ1 during light irradiation that is sufficiently large as an electrophotographic photoreceptor, and has good photosensitivity (particularly to light in the visible and infrared regions). 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 contains a-3iC:11 or a-3t containing at least C10.
(Co): J
below 101,000 cJl-2, preferably 6,000
cra-2 or less, more preferably 3.000 cu-
It is set within a specific range of 2 or less.

By limiting the infrared absorption area in the vicinity of the wave number due to 5i-CH3 of the surface-modified l1i45 to a specific range, the mechanical strength, especially the scratch resistance, of the surface-modified layer 45 is significantly improved. was discovered for the first time.

Regarding the composition of the surface modified layer 45, 10a t+a%≦(C) or (C+O)≦100at
+s% (However, (S i ) + (C) = 100
atm% or (S i) + (C) + (0) =
100atm%) is desirable, and 40at+m%≦[c] or (C+0)≦70atm
% (here, atm % is, for example, (B2Hs)/(S i H4) in order to improve the charging ability of the atomic surface-modified layer 45 in the later-described black discharge method.
= 10''3~10'capacity ppm, preferably 1 leaf i
~102 ppm by volume of elements of group IA of the periodic table, or doped with elements of group VA of the periodic table of (PHa)/(SiH+) = 10 to 104 ppm by volume, preferably 1 to 102 ppm by volume. It is better to do so.

Further, the thickness of the surface modified layer 45 is desirably 200 to 30,000 thick, more preferably 1,000 to 10,000 thick. If the film thickness is too large, the residual potential V becomes too high and the photosensitivity decreases, resulting in a-3
It is easy to lose the good characteristics as a t-type 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 composed of a-3i:H (its composition is 11 in 5-40aL).
m%, and when containing halogen in place of or in combination with I, halogen 5 to 40a ta+%
, or the content of H and halogen is 5 to 40a ts+
It is better to set it as %. This photoconductive layer 43 is preferably doped with an impurity, particularly an element from group IA or VA of the periodic table, in order to improve charging performance. For example, during glow discharge described below,
(BHe)/(S iH+) ~ 10-3 ~ 100 (preferably 10-2 ~ 10) volume ippm, (PH3)/
(S 1H4)=10″3~100 (preferably 10
-2 to 10) Capacity ppm may be used.

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 IIA 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-5i:H (H-containing IF 5-40 ats%): (B
2 Hs) / (S i H4) = 10'~10
4 volume ppm (even 10-1 to 102 volume ppm)
(PH3)/(S iH+)-10″3 to 104 volume ppm (further 10-1 to 102 volume ppm) a-3
iC:H (H content 5~50at11%, C content 5~
100 at-%): (B z He]/ (S i H4) = 10″3~
106 capacity ppm (furthermore 10-1 to 104 capacity ppm
) (PH3)/(S 1H4) = 10' to 106 capacity ppm (further 1o-t to 104 capacity ppm theory) a-3
iN:H (H content 5-50at+w%, N content 5-50at+w%
60a): (B z Hs) / (S i H4) = 1(1'
~106 capacity pps+ (furthermore 10-1~104 capacity p
pm)(PH3)/(S1H4)=10'~10
6 capacity pp+* (and 10-1 to 104 capacity ppm
) 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 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 1ii (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
j! , Ga, In, T1, etc. can be used, and in addition to phosphorus, elements of Group VA of the periodic table such as As, sb, etc. can be used.

Next, a method for manufacturing the above-mentioned photoreceptor (eg, drum-shaped) and its apparatus (glow discharge device) will be explained with reference to FIG.

A drum-shaped substrate 41 is vertically rotatably placed 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 S i H4 or a gaseous silicon compound, 63 is a supply source of hydrocarbon gas such as CI 4, and 64
65 is a supply source of nitrogen compound gas such as 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 (for example, B2H6) supply source, 6
8 is each flow meter. In this glow discharge device, first, the surface of a support, for example, an A2 substrate 41, is cleaned and then placed in a vacuum chamber 52, and the gas pressure in the vacuum chamber 52 is reduced to 1.
The temperature of the substrate 41 is adjusted to 0-6 Torr and evacuated, and the substrate 41 is heated to a predetermined temperature, particularly 100 to 350°C (preferably 1
50-300°C). Next, a high purity inert gas is introduced into the carrier, e.g. 0.01 to 1Q Tor.
A high frequency voltage (for example, 13.56 Mllz) is applied by a high frequency power supply 56 under a reaction pressure of r. by this,
Each of the above reaction gases is decomposed by glow discharge between the electrode 57 and the substrate 41, and a-3i:H, a-3i:H, a-3i
C:H is deposited as layers 44, 43, 45 as described above on the substrate in succession (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-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, a halogen such as fluorine is introduced in the form of SiF4 instead of the above H or in combination with I, and a-3i :F, a-3i
:H:F, a-3iN:F.

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, JP-A-56-78413 by Junto Motoyama (JP-A-54-152)
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 the support, for example, a drum-shaped A2 group Fi41 with a smooth surface, it is placed in the 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, high-frequency power with a frequency of 13.56 MHz was applied under a back pressure of 0.5 Torr, and preliminary discharge was performed for 10 minutes. Next, a reaction gas consisting of SiH4 and BzHa was introduced at a flow rate ratio of 1:1.
: (Ar+S iH4+ of (1,5Xl0-3)
B2H6) By glow discharge decomposition of mixed gas,
A P+ type a-3i:H layer 44 having a charge pro-noking function was formed to a predetermined thickness at a deposition rate of 6 pm/hr.

Subsequently, the flow rate was 1: 1: (5xlO-6
) (Ar+SiH4+B2H6) mixed gas was subjected to discharge decomposition to form a boron-doped a-3i:8 layer 43 of a predetermined thickness. Subsequently, the impurity gas supply is stopped and the flow rate ratio is 4.
0:3:90 (Ar:5tH4:CH4) mixed gas at reaction pressure p = Q, 5 Torr, discharge power R1 = 4
Glow discharge decomposition was performed at 00 W to form an intermediate layer of a predetermined thickness, and further, (Ar: S 1
)14:CFI4) Mixed gas at reaction pressure P = 1.
Glow discharge decomposition was performed at 0 Torr and discharge power Rf=400 W to further provide a surface protective layer 45, thereby completing an electrophotographic photoreceptor. Note that when the surface layer 45 was made of a-3iCO, CO2 was used as the oxygen source. Next, various tests were conducted using each of the photoreceptors described above as follows.

Using a modified electrophotographic copying machine U-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.

■ If there is a paper jam, let it run for 30 seconds.

■ Repeat ■ and ■ 30 times.

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

○ No jamming scratches △ Several jamming scratches occurred × Many jamming scratches occurred
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, print an image using the above-mentioned copying machine, and check the load at which white streaks appear on the image.
Let this be the scratch strength (g) of the photoreceptor.

The results are summarized in Table 1 below. From these results, it can be seen that if the photoreceptors (Fish 1 to 4) are prepared according to the present invention, photoreceptors particularly excellent in scratch resistance for use in electrophotography can be obtained.

Table-1 *Wave number 1240cm caused by 5i-CH3 mentioned above-
The infrared absorption area S near the photoreceptor 1 to 7 is actually determined by depositing the film material of each surface modification layer on the Si wafer by the method described above. Each obtained sample was subjected to an infrared spectrometer to measure the infrared absorption spectrum, and calculations were made from the infrared absorption spectrum. Among these, for example, photoreceptor 1Ilhl, 2.3.5.7
Infrared absorption spectrum diagram and its wave number 1240c
An enlarged view of the vicinity of m-' is shown in Fig. 4A and Fig. 4B (
1), Figures 5A and 5B (lth2), Figures 6A and 6B (corner 3), Figures 7A and 7B (11k
L5), as shown in Figures 8A and 8B (Nl17). In these figures, d is the thickness of the surface modified layer, and S
The composition ratio (a Lm%) of i % C10 is also shown. In addition, the infrared absorption area S is also written in each enlarged view. however,
Regarding the amount of 0, approximately 0.1 or 0.2 atn+% can be considered to be almost zero.

From these spectrograms, it can be seen that the infrared absorption area S of the surface modified layer tends to change depending on the C and O contents. However, if the amount of 0 is increased, the film structure will be disturbed (S
It is thought that due to disturbance of the network structure due to i CH3 etc., absorption becomes broad and S becomes thicker than necessary.

In addition, in the above method, it was found that the infrared absorption intensity of 5i-CH3 was decreased by lowering the reaction pressure. Also, the ratio of the dark resistance (ρD) of the photoreceptor to the resistance during light irradiation (pL): ρ.

/ρ approaches 1.0 as the reaction pressure increases, and as the reaction pressure increases, S, D, (Spin de
nsity pin density = dangling bond density)
It has also been found that the absorption area S due to 5i-CH3 changes depending on the CH4 flow rate and reaction pressure when forming a thickened layer. To explain this below, first, CH4
The influence of flow rate was measured under the following conditions and is shown in Table 2 below.

Article-Note S i 84 = 15 SCCM A r = 200SCCM Rf = 400W P = 0.5 Torr (Margin below, continued on next page.) Table-2 Also, control using reaction pressure is shown below.

row-bean S i H4=15 SCCM CH4=450SCCM A r = 200SCCM Rf = 400W Table-3

[Brief explanation of the drawing]

1 to 8 show examples of the present invention, in which FIG. 1 is a sectional view of an a-3t 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. A schematic diagram of the scratch strength tester; Figures 4A, 5A, 6A, 7A, and 8A are infrared absorption spectra of the surface modified layer of each photoreceptor; Figures 4B and 5B; , FIG. 6B, FIG. 7B, and FIG. 8B are enlarged views of essential parts of the same infrared absorption spectrum. 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.

Claims (1)

[Claims] 1. A surface modified layer made of amorphous hydrogenated and/or halogenated silicon containing at least carbon atoms and oxygen atoms, and an infrared ray measured for this surface modified layer. Absorption curve wave number 1200-1300cm
The integral area (S) at ^-^1 is ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [However, a(ω)=-(1/d)log_1_0I(ω
)/Io, 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,
Io is the incident light intensity. ] Photoreceptor within the range shown.