JPS62222259A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To prevent the surface potential of a photosensitive body from changing by using an Se-Te-Te-Cl type alloy doped with <=0.1ppm O and 2-15ppm Cl. CONSTITUTION:The Se-Te-Te-Cl type alloy doped with <=0.1ppm O and 2-15ppm Cl is used for the electrophotographic sensitive body, thus permitting a doping amount of Cl to be saved, residual potential accumulation (fatigue characteristics) to be improved, and drop of acceptance potential and change of surface potential of the photosensitive body to be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an electrophotographic photoreceptor, and particularly to an electrophotographic photoreceptor made of a selenium-tellurium-chlorine (hereinafter referred to as 3e-Te-CI) alloy.

[Prior Art] Conventional 3e-Te photoreceptors have been used without knowing the oxygen concentrations contained in the raw materials Se, Te, and their alloys, and the oxygen concentrations in the photoreceptors have not been quantified. It is known that in the conventional photoreceptor, as the Te1 degree increases, the panchromaticity increases, the sensitivity becomes faster, and at the same time, the so-called fatigue characteristic that residual potential accumulates due to repeated use increases. Various improvements have been attempted in this regard, and one method is doping with CI (chlorine).

However, the fatigue phenomenon of residual potential accumulation is caused by deep carrier trap levels in the photoreceptor, and CI
Doping is necessary to form a shallow trap level and make it easier to release carriers trapped in deep units, but the formation of a shallow trap level also causes them to be thermally excited and released. This has the disadvantage that the surface charging potential tends to decrease as the temperature of the photoreceptor increases.

Commercial products used to date nominal value 99, 99-9
Although no impurities were known to be sufficient to form deep traps in photoreceptors made using 9.999% Se and Te, recently established analytical methods revealed that the raw materials 3e, T
'e, It has become clear that the level of oxygen concentration in the alloy and, by extension, in the photoconductor manufactured using the same greatly contributes to fatigue characteristics, and efforts have been made to reduce the oxygen concentration in the photoconductor. There is.

However, if a photoconductor is conventionally made from an alloy using 3e and Te with a low oxygen concentration, although the fatigue characteristic of residual potential accumulation is improved, the eJ effect is inevitable, in which the potential drop at high temperatures becomes significant.

This is because C1 is effective when there is a large amount of oxygen forming deep units, but when the amount of oxygen is small, C1 has an excessive compensation effect.

[Information] This invention aims to improve the fatigue properties of conventional alloys by reducing the doping J of C1, while at the same time preventing the surface potential from changing.

[Structure] The structure of the present invention for quickly achieving the above object is that the oxygen doping amount is 0.1 ppln or less and the C1 doping amount is 2 to 15
This is a photoreceptor for electrophotographic pages, characterized in that it is made of a selenium-tellurium-chlorine alloy in a ppm range.

That is, when the amount of oxygen in the photoreceptor is small, by limiting the doping amount of C1 to the above-mentioned specific range, both characteristics of residual potential accumulation and potential drop are improved.

The structure of the present invention will be specifically explained below with reference to Examples.

Example 1 Commercially available Se with nominal purity of 99.999% and 99.999
% of commercially available Te, using conventional C1-doped steel (20~
301) I) m) Te An alloy is manufactured with a composition of 5 to 15 wt%, and is deposited at a vacuum level of 10-5 orr or higher to a film thickness of 50%.
tim photoreceptor was created.

Charge the photoreceptor with a current of 50 μA and an illuminance of 1000
The surface potential was measured while repeating simultaneous exposure with a lux quenching lamp. The increase m in potential after 500 repetitions was compared as the residual potential increase vR.

In addition, the photoreceptor was charged for 20 seconds with a charging current of 10 μA in an atmosphere of the measurement environment temperature, air temperature (20'C) and 35°C, and the difference in charging potential between air temperature and 35°C was charged. Comparison was made as N potential change ΔV.

Next, the same photoreceptor was peeled off, and the amount of dissolved oxygen was measured by spectrophotometry using pararosaniline, and the amount of Cl dope was measured by fluorescent X-ray and activation analysis.

The above results are shown in Table 1.

Table 1 172〒≦ Note) Conventionally used Se and Dice are N028 and the oxygen content is 1 each.
0 and +ooppi.

From the results in Table 1 above, it can be seen that the doped C1 is the conventional 13~
At 20 ppH+ level, the oxygen content is 0,2E)E)
When it becomes 111 or more, the residual potential increases VF? is high and C1
It can be seen that it is not practical unless the doping amount is changed roughly. Oxygen doping jlo of 2 to 10 ppm is the quality of a conventional photoreceptor, but it is desirable that the increase in residual potential (fatigue) be close to zero, and this is a level that must be improved. Oxygen content is 0. At levels below lppm, the residual potential increases V
It can be seen that although R is low and good, the change in charging potential is greatly reduced, so that it cannot be used practically.

Example 2 Using 99.999% 3e and Te with a small amount of oxygen doping, an alloy with a reduced amount of C1 doping was produced, and Example 1
Measurement of photoreceptor properties and oxygen concentration,
C1 dope ■ was analyzed.

The results are shown in Table 2.

Table 2 As a result of the above Table 2, for a photoreceptor with a small amount of oxygen doping, a C1 doping amount of 15 ppm or more causes a large change in charging potential, which is unsuitable, and a C1 doping amount of 2 ppm or less causes a too large increase in residual potential, making it unsuitable. The amount of oxygen is 0. For photoreceptors with lppm or less, the C1 doping amount is 2 to 15 ppm, especially 5 to 12 ppm.
It can be seen that the optimum value is m.

Example 3 Various types of 3e (99,999%) with different oxygen doping amounts
Two types of master alloy groups doped with 1 and 25 ppm and 15 ppm of Te are prepared, and the same grade of Te as in Example 2 is separately co-evaporated using an evaporation source to form a film having the same Te composition ratio as in Example 1.2. A 3e-Te photoreceptor having a thickness of 50 μm was prepared, and its properties and density were measured in the same manner as in Example 1. The result is the third
Shown in the table.

Table 3 As a result, the same results as in Example 1.2 were increased by 1 depending on the amount of oxygen in the photoreceptor.

Example 4 25 ppm of C1 and 5 ppm of i5ppm were added to various types of Te with different amounts of oxygen doping and Se with a small amount of oxygen doping.
Example 1 Co-depositing different types of master alloys using different evaporation sources
．． A 5e-Te photoreceptor having a film thickness of 50 μm and having the same Te composition ratio as Example 2 was prepared, and its characteristics and concentration were measured in the same manner as in Example 1. The results are shown in Table 4.

Table 4 Results The same results as in Example 1.2 were obtained depending on the amount of oxygen in the photoreceptor.

Example 5 CC115pp for Se and Te with low oxygen doping loss
A 5e-Te-CI alloy containing 5e-Te-CI was produced, and before vapor deposition, the vapor deposition pot was replaced with oxygen gas, and the vapor deposition was performed at various degrees of vacuum to obtain a 50 μm photoreceptor, and the characteristics and concentration were measured in the same manner as in Example 1. did. The results are shown in Table 5.

Table 5 The results show that photoreceptors deposited under conditions of high oxygen partial pressure contain a large amount of oxygen and have poor fatigue characteristics.

This is consistent with the fact that during normal vapor deposition, leakage occurs in the true thinning device, causing fatigue characteristics in photoreceptors manufactured under abnormal conditions.

Furthermore, from the above examples, the amount of C1 doped in the photoreceptor was reduced to 50 to 70% of that in the master alloy, and the amount of oxygen was reduced to 1/10 to 1/100. It can be seen that the quality characteristics of the photoreceptor can be better maintained by specifying not only the CI and oxygen content of the vapor deposition base material but also the CI and oxygen content in the photoreceptor.

[Effect 1] The present invention can improve residual potential accumulation (fatigue characteristics) of a 3e-Te photoreceptor and also prevent a decrease in charging potential. In addition, the Cl doping in the raw materials can be reduced to the greatest extent and costs can be reduced.

Claims (1)

[Claims] Oxygen doping amount is 0.1 ppm or less and chlorine doping amount is 2
An electrophotographic photoreceptor comprising a selenium-tellurium-chlorine alloy having a content of selenium in the range of 15 ppm to 15 ppm.