JPS6236675A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve fatigue characteristics of an electrophotographic sensitive body by doping a selenium photosensitive layer of a single layer type or a composite layer type with an amount of oxygen not above a specified value. CONSTITUTION:The selenium layer of the single or composite layer type photosensitive layer is doped with oxygen, and its doping amount is measured and regulated to <=0.05ppm, thus permitting the fatigue characteristics of the photosensitive body to be improve.

Description

[Detailed Description of the Invention] Technical Field This invention relates to Se (selenium) based vapor I? It relates to an electrophotographic photoreceptor having a film, and can also be applied to photoelectric elements.

Prior Art 3e photoreceptors are required to have various characteristics when used as electrophotographic photoreceptors, but one of the problems is the upper limit of residual potential due to repeated use.

Countermeasures have been considered to address this issue, such as doping with halogen to prevent the increase in residual potential, but this has resulted in the problem of an increase in internal temperature as a side effect.

As a result of various analyses, it has become clear that the reason for the increase in residual potential is the influence of oxygen contained in Se.

Therefore, the amount of oxygen doped in 3e has been specified as the base material for vapor deposition, but the amount of oxygen in the photoreceptor formed by vapor deposition does not have a one-to-one correspondence with the amount of oxygen in the base material for vapor deposition. However, their relationship remained unknown.

This time, as a result of making photoreceptors using various vapor-deposited base materials, directly measuring the amount of oxygen doped in the photoreceptor, and studying the correspondence with the characteristics of the photoreceptor, the relationship between the characteristics of the photoreceptor and the amount of doping was clearly established. became.

Consequently, the present invention aims to improve the electrophotographic fatigue properties in Se photoreceptors, particularly by reducing the content of impurity oxygen.

Structure The structure of the present invention to achieve the above object is a Se-based electrophotographic photoreceptor in which the amount of oxygen doped in the Se vapor-deposited film is 0.05 ppm or less.

Through various experiments, it has been found that the amount of oxygen m in the photoreceptor is 1/10 to 1/100 of the amount of oxygen in the vapor deposition base material.

The reason for this is that the oxygen in the Se vapor deposition base material is Se o, S
It evaporates in the form of e02, but its high vapor pressure and weak directivity reduce the proportion of it incorporated into the deposited film.In addition, it becomes a residue in the deposition base material as a metal oxide, and oxygen is inevitably the source of evaporation. This is because it will be left behind.

In short, vapor deposition is a type of distillation action, and it is also affected by the atmosphere such as the degree of vacuum and oxygen partial pressure during vapor deposition, so it is difficult to guarantee the characteristics and quality of the photoreceptor based only on the amount of oxygen in the vapor deposition base material. 5! It is clear that it is effective to directly measure the oxygen content in the photoreceptor and adjust it.

The relationship between oxygen in a photoreceptor and its characteristics will be specifically explained below with reference to Examples.

Example 1 A photosensitive plate having a film thickness of 50 μm was prepared by crucible vapor deposition using commercially available SC materials from various manufacturers with a nominal purity of 99,999% at a degree of vacuum of 10-5 Torr or more.

The test method for the photosensitive plate made in this way is that the charging current is 50
The surface potential is measured while repeating simultaneous exposure with a quenching lamp of 0 μA and illuminance of 1000 l×.

The increase in potential after 500 repetitions is the increase in residual potential V D
800 and compare each Se material.

Next, the oxygen doping level of the same Sc material and the vapor-deposited photosensitive film peeled from the substrate was measured by spectrophotometry using pararosaniline.

Table 1 From the results, it can be seen that the increase in residual potential corresponds to the amount of oxygen in the deposited film, and that the residual potential increases suddenly when the oxygen dope m becomes 0.05 ppm or more.

Example 2 [Oxygen doped fi 1.41) 111 added to Example 1
3.11 and 11.5ppm. A photosensitive plate treated with 13111.5 ppm of oxygen and commercially available 99.99% Te was used on a photosensitive plate treated with ff%l of 1”elowt%.
A two-layer type photosensitive plate was prepared by depositing 5 μl of 3e-Te alloy.

Regarding this photosensitive plate, the increase in residual potential was measured in the same manner as in Example 1, and the results shown in Table 2 were 1!7.

Based on this result, when choosing a two-layer type, due to the effect of the second layer,
It can be seen that although the residual potential increases, the difference due to the oxygen doping m in Se at the -fflth point is maintained as it is.

Effect As explained above, the amount of oxygen in the So photoreceptor was reduced to 0.05p.
By reducing the amount below pm, the fatigue characteristics of the photoreceptor can be improved.

Claims (1)

[Scope of Claims] An electrophotographic photoreceptor characterized in that the amount of oxygen doped in the Se layer in the Se single-layer photoreceptor or composite layer photoreceptor is 0.05 ppm or less.