Kabushiki Kaisha Toshiba

Akira Sanjoh

Shuji Yoshizawa

Wataru Mitani

Mariko Yamamoto

Tsuyoshi Ueno

An electrophotographic photosensitive member comprises a conductive substrate, a blocking layer formed on the conductive substrate, a photoconductive layer, formed on the blocking layer and a surface layer formed on the photoconductive layer. The blocking layer is formed from a microcrystalline silicon, which is made a p-type by being heavily doped with an element of Group III of the Periodic Table. The photoconductive layer is formed from an amorphous silicon which is lightly doped with an impurity element, and which is similar in properties to an intrinsic semiconductor. Rectifying contact is formed between the photoconductive layer and the blocking layer so that a depletion layer is formed by that interface toward the interior of the photoconductive layer. By so doing, it is possible to obtain a photosensitive member having a high sensitivity in the range from visible light to near-infrared light.

Electrophotographic photosensitive member

In an electrophotographic photosensitive member according to the present invention, a barrier layer is formed on a conductive substrate; a first layer of a photoconductive layer on the barrier layer, and a second layer on the first layer. Formed of microcrystalline silicon containing hydrogen, the first layer is highly sensitive to long-wavelength light. The second layer contains hydrogen and at least one element selected from carbon, oxygen, and nitrogen. The barrier layer is formed of microcrystalline silicon containing an element included in group III or V of the periodic table. The rectifying action of the barrier layer prevents carriers from being injected into the photoconductive layer from the substrate side. Containing carbon, oxygen, or nitrogen, the barrier layer has high dark resistance and chargeability.

Electrophotographic photosensitive member using microcrystalline silicon

In an electrophotographic photosensitive member according to the present invention, a barrier layer is formed on a conductive substrate, and a photoconductive layer on the barrier layer. The photoconductive layer is formed of a microcrystalline silicon layer, whose crystallinity varies all the way through its thickness. The higher the crystallinity of the microcrystalline silicon layer, the more distinguishable are the crystalline properties, the narrower is the optical band gap, and the higher is the sensitivity to long-wavelength light. If the crystallinity becomes lower, then the amorphous properties are enhanced, and the resistance is increased in proportion. Thus, the chargeability and the sensitivity to long-wavelength light of the microcrystalline silicon layer can be improved by varying its crystallinity in the photoconductive layer.

In an electrophotographic photosensitive member according to the present invention, a barrier layer is formed on a conductive substrate, and a photoconductive layer on the barrier layer. Formed of microcrystalline silicon, the photoconductive layer is highly sensitive to long-wavelength light. The barrier layer is formed of microcrystalline silicon containing an element included in group III or V of the periodic table. The rectifying action of the barrier layer prevents carriers from being injected into the photoconductive layer from the substrate side. Containing carbon, oxygen, or nitrogen, the barrier layer has high dark resistance and chargeability.

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Aichi, Japan

Akira Sanjoh