JPS6043664A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body which has substantial photoconductivity in a long wavelength region and has excellent printing resistance by providing an Se-Te alloy layer having a specific content of Te on a conductive base body in a specific layer thickness range and providing a pure Se layer within a specific layer thickness range on said layer. CONSTITUTION:An Se-Te alloy contg. 15wt% Te is deposited by evaporation on a conductive base body 1 consisting of an Al tube or the like to 0.5-2mu thickness to provide an electric charge generating layer 2. The base body temp. is then maintained at <=40 deg.C and pure Se is deposited by evaporation on said layer to 10-50mu thickness to form an electric charge transfer layer 3. The photosensitive body which has high performance to hold electric charge, has substantial photoconductivity in a long wavelength region of >=600nm when a light source such as a semiconductor laser, LED or the like is used and has good mechanical strength and printing resistance is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-sensitivity electrophotographic photoreceptor used in a non-impact electrophotographic printer or an intelligent copier using a light source such as a semiconductor laser or an LED.

[Prior art and its problems] In this type of photoreceptor, the output wavelength of the solid-state element used as a light source is in the long wavelength region of 600 nm or more.
It is necessary to have sufficient photoconductivity in that area. Therefore, photoreceptors have been proposed that have organic semiconductors such as copper phthalocyanine as a charge generation layer and pyrazoline or the like as a charge transport layer, but the use of organic materials as the charge transport layer has problems with its mechanical strength. Therefore, it is impossible to provide sufficient printing durability. Also, in the case of amorphous Si-based photoreceptors, which have been applied to this field in recent years,
It does not have photoconductivity in the vicinity of nm, and doping with Ge or the like is required. However, such doping is an energy source. This results in a narrowing of the energy gap, resulting in a lack of stability as a photoreceptor.

Among the selenium-based photoreceptors that are most commonly used as electrophotographic photoreceptors, for example, As2Se, which has good printing durability, is used.
Type 2 is soo nm similar to amorphous silicon.
It cannot be used for light of nearby wavelengths, and in order to be sensitive to such light, S containing 40% by weight of Te is added.
A charge generation layer of e.g. 1 μm thick made of e.g. is provided on a charge transport layer of e.g. 60 μm thick made of pure Se or a low concentration Te-Se alloy. The manufacturing process is extremely complicated, and it is difficult to obtain stable characteristics.

[Purpose of the invention]

An object of the present invention is to provide an electrophotographic photoreceptor that has a simple layer structure, is sensitive to light in a long wavelength region, and has sufficient printing durability.

[Key points of the invention]

The present invention provides Se with a Te content of 15% by weight on a conductive substrate.
The above object is achieved by sequentially laminating a charge generation layer made of -Te alloy with a thickness of 0.5 to 2 Pm and a charge transport layer made of pure Se with a thickness of 10 to 50 μm. . At this time, the Te content can be changed depending on the type of light source used, but in order to have usable photoconductivity in a long wavelength region of 600 nm or more, it is necessary to contain at least 15 wt%. A thickness of 0.5 μm or more is sufficient for the layer containing Te to have the desired photoconductivity. However, if the thickness is 2 μm or more, the charge retention ability of the layer as a whole decreases, which is not preferable. Next, when the carriers generated in the charge generation layer cancel out the charges formed on the surface of the photoreceptor using means such as corona charging, the carriers are easily removed when forming an electrical or electrical latent image. It is necessary to form a charge transport layer that has the ability to move the surface charge and sufficiently retain the surface charge in other regions. In this case, since the carriers are electrons, they need to have sufficiently high electron mobility. Furthermore, due to its printing durability and charge retention performance, pure Se is the most suitable material for this type of material.
However, the electron mobility of pure Se is smaller than that of holes, and when the transport layer is formed by vacuum evaporation, it depends greatly on the temperature of the substrate, so the film thickness is A thickness of 10 μm or more is required to have a sufficient surface potential, and if it exceeds 10 μm, problems will arise in followability to process speed.

[Embodiments of the invention]

Figure 1 shows the layer structure of the photoreceptor according to the present invention, in which the Te content is 15% by weight or more on a conductive substrate such as aluminum, copper, brass, or conductive-treated plastic or paper. A charge generation layer 2 having a film thickness in the range of 0.5 to 2 μm is formed using a Se-Te alloy using a method such as vacuum evaporation.

On top of that, a charge transport layer 3 made of pure Se is formed using the same method.
It is formed in a thickness range of 0 to 50 μm.

Experimental Example 1: After smoothing the surface of an aluminum tube 1 with a diameter of 90 mg and a length of 320 mm, it was immersed in a BN')z solution to form an oxide film on the surface, and the tube was mounted on a rotating shaft in a vacuum chamber. do. After maintaining the temperature of the substrate at 65° C., a layer 2 made of a Se-Te alloy having a Te content of 25 Ttj was formed by vacuum evaporation. At this time, the thickness of the charge generation layer 2 was set to 0.00000.
Samples A, B, and C were prepared to have a thickness of 5 μm, 2 μm, and 5 μm. Next, after mounting these samples on the same rotation 11111, the temperature of the substrate was maintained at 35'O, and a charge transport layer 3 made of pure Se was formed to a thickness of 35 μm. The electrical properties of these samples are shown in Table 1.

Here, the dark decay rate shows the value after 1 second, and the half-decay exposure rate is 7
This is the value required for the initial potential of 600 V to attenuate to 300 V by irradiating light with a wavelength of 80 nm.

Table 1 Experimental Example 2: After forming a charge generation layer 2 of 1.0 μm in the same manner as in Experimental Example 1, the temperature of the substrate was increased to
Table 2 shows the results of the same measurements as in Experimental Example 1 for Samples E, F, and G in which pure Se%i3 was formed.

From Table i2, Table 2 shows that when the temperature of the substrate exceeds 40°C, it is impossible to achieve a practical electron mobility.

The above samples A and E were attached to a commercially available laser printer and 50,000 copies were printed, and the 50,000th image was A.
No change was observed in both E and E. On the other hand, when copying is carried out using a commercially available copying machine using, for example, an organic semiconductor PVK as a photosensitive layer, the level becomes unusable after the 30,000th image.

〔Effect of the invention〕

The present invention uses Se-'re with a thickness of 05 to 2 μn1 on the base side.
Although the photoreceptor has an extremely simple structure of three layers including the base, it has a charge generation layer made of an alloy and a charge transport layer made of pure Se on top of it. It becomes possible to provide at a low cost a photoreceptor that has sufficient photocontamination resistance even in the above long wavelength range and has sufficient 11 resistance.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the structure of a photoreceptor for 'iβ-photography according to the present invention. DESCRIPTION OF SYMBOLS 1... Conductive base, 2... Charge generation layer, 3...' Charge transport layer. Figure 1

Claims (1)

[Claims] 1) 5e-1 with a tellurium content of 15% by weight on a conductive substrate
1. A photoreceptor for electrophotography, characterized in that a charge generation layer made of a zero alloy and having a thickness of 05 to 2 μm and a charge transport layer made of pure Se and having a thickness of 10 to 50 μm are laminated in sequence.