Hitachi, Ltd.

Nippon Hoso' Kyokai

Naohiro Goto

Keiichi Shidara

Yasuhiko Nonaka

Tadaaki Hirai

Yukio Takasaki

Kenkichi Tanioka

Tatsuro Kawamura

Kazutaka Tsuji

Tatsuo Makishima

Takashi Yamashita

Eisuke Inoue

Tsuyoshi Uda

Masaaki Aiba

Eiichi Maruyama

Junichi Yamazaki

Sachio Ishioka

Kenji Sameshima

Kazuhisa Taketoshi

Hirofumi Ogawa

Eikyuu Hiruma

Mitsuo Kosugi

Shiro Suzuki

Hideaki Yamamoto

Tsutomu Fujita

Eikyu Hiruma

Yochizumi Ikeda

Motoyasu Terao

Yasuo Tanaka

Hiroaki Hachino

Masanao Yamamoto

Chushirou Kusano

Hirokazu Matsubara

Shirou Suzuki

Toru Takigawa

Yukinao Isozaki

Yoshizumi Ikeda

Yasushi Saitoh

Saiichi Koizumi

Keiko Ooki

Yohitsumu Ikeda

A photoconductive device having a photoconductive layer which includes an amorphous semiconductor layer capable of charge multiplication in at least a part thereof is disclosed. The method of operating such a photoconductive device is also disclosed. By using the avalanche effect of the amorphous semiconductor layer, it is possible to realize a highly sensitive photoconductive device while maintaining low lag property. In one aspect of the present invention, the amorphous semiconductor layer is amorphous Se. In another aspect of the present invention, the amorphous semiconductor layer is composed mainly of tetrahedral elements including at least an element of hydrogen or halogens. When using the amorphous semiconductor layer composed mainly of tetrahedral elements, the charge multiplication effect is produced mainly in the interior of the amorphous semiconductor, and thus it is possible to obtain a thermally stable photoconductive device having a high sensitivity while keeping a good photoresponse.

Photoconductive imaging apparatus

A photoconductive device having a photoconductive layer which includes an amorphous semiconductor layer capable of charge multiplication in at least a part thereof is disclosed. The method of operating such a photoconductive device is also disclosed. By using the avalanche effect of the amorphous semiconductor layer, it is possible to realize a highly sensitive photoconductive device while maintaining low lag property.

Photoconductive device and method of operating the same

A target of an image pickup tube, having a transparent substrate, a transparent conductive film, a p-type photoconductive film made mainly from amorphous Se, and an n-type conductive film capable of forming a rectifying contact at the interface with the p-type photoconductive film, using the rectifying contact as a reverse bias, characterized in that the p-type photoconductive film containing at least a region having more than 35%, and to 60% by weight of Te in the film thickness direction, and at least a region containing 0.005 to 5% by weight of at least a material capable of forming shallow levels in the amorphous Se in the film thickness direction, has good after-image characteristics even if operated at a high temperature.

Target of image pickup tube

A photoconductive image pick-up tube target comprising an N-type semiconductor film formed on a transparent substrate, and a P-type photoconductive film in rectifying contact with the N-type semiconductor film and containing Se and As and also Te as sensitizers. A layer of said P-type photoconductive film between the N-type semiconductor film and a Te-containing layer of the P-type photoconductive film has an As concentration distribution which is lower on the side of the N-type conductive film and higher on the side of the Te-containing layer.

Photoconductive image pick-up tube target

A photoconductive target having an electrode and a P-type conductive layer mainly made of Se and making rectifying contact at an interface with the electrode, with at least Te being doped in a portion of the P-type conductive layer. At least one metal fluoride forming shallow levels is doped in the region where the signal current is generated for the most part of the P-type conductive layer with an average concentration of not less than 50 ppm and not more than 5% by weight. The metal fluoride is preferably at least one selected from the group consisting of LiF, NaF, MgF.sub.2, CaF.sub.2, BaF.sub.2, AlF.sub.3, CrF.sub.3, MnF.sub.2, CoF.sub.2, PbF.sub.2, CeF.sub.3 and TlF. The high light sticking of the photoconductive target can thus be considerably reduced.

Photoconductive target

A photoelectric device comprises a signal electrode, a layer of amorphous photoconductor containing 50 atomic percent or more of selenium and an N-type semiconductor layer made of a material selected from the group consisting of oxygen depletion type cerium oxide and oxygen depletion type lead oxide and disposed therebetween, which has a thickness greater than 8 nm and up to and including 500 nm and a Fermi level located within an energy range of 0.2 to 0.8 eV from the bottom of a conduction band.

Semiconductor layer of oxygen depletion type cerium oxide or lead oxide

The target comprises a transparent substrate, an N-type transparent conductive film formed on the substrate, a P-type photoconductive film formed on the N-type conductive film and a heterojunction formed at the interface between the N- and P-type films. The P-type photoconductive film contains selenium, tellurium and arsenic of which selenium and arsenic are distributed continuously from the heterojunction throughout the thickness of the P-type photoconductive film whereas the distribution of tellurium is spaced from the heterojunction and localized in the vicinity of the heterojunction. The total amount of arsenic contained in the P-type photoconductive film ranges from 2.5 to 6% by weight.

Targets for use in photoconductive image pickup tubes

A photoconductive film comprises a first region containing Se in which Te and an element capable of forming deep levels in Se are added at concentrations lower than 10 atomic % inclusive on average, respectively, a second region disposed on the first region and containing Se in which Te is added with a continuous distribution of concentration having a peak value greater than 15 atomic % inclusive, a third region disposed on the second region and containing Se in which an element capable of forming deep levels in Se is added with a continuous distribution of concentration having a peak value greater than 15 atomic % inclusive, and a fourth region disposed on the third region and containing Se in which Te and an element capable of forming deep levels in Se are added at concentrations lower than 10 atomic % inclusive on average, respectively.

Photoconductive films

In a method of manufacturing a target structure for use in a photoconductive image pickup tube when depositing a P-type photoconductive film on an N-type transparent conductive film deposited on one side of a transparent substrate which acts as an incident window of the image pickup tube, the P-type photoconductive film is made up of first and second photoconductive substances. The commencement of the deposition of the first photoconductive substance is delayed a predetermined time than that of the second photoconductive substance and the deposition of the first photoconductive substance is terminated before completion of the deposition of the second photoconductive material thereby forming a layer of the first photoconductive substance not contiguous to the junction between the N-type transparent conductive film and the P-type photoconductive film and having a predetermined thickness.

Target structure for use in photoconductive image pickup tubes

In a target structure for use in a photoconductive image pickup tube, a P-type photoconductive film is deposited on an N-type transparent conductive film which is deposited on a transparent substrate. The P-type photosensitive film comprises first and second photoconductive substances. The commencement of the deposition of the first photoconductive substance is delayed a predetermined time from that of the second photoconductive substance thereby forming a film of the first photoconductive substance which is not contiguous to the junction surface between the N-type transparent conductive film and the P-type photoconductive film.

Target structures for use in photoconductive image pickup tubes and

An image pickup tube target wherein a rectifying contact which is formed at a boundary of a first layer of a material selected from the group consisting of tin oxide, indium oxide, titanium oxide, cadmium sulfide, zinc sulfide, cadmium selenide, zinc selenide, n-type germanium, n-type silicon and mixture thereof, and a second layer of a material mainly consisting of selenium and including halogen, is reversely biased and operated at a region where signal current is saturated with respect to applied voltage. The second layer of the material includes 50 atomic percent or more of selenium and 0.1 - 1000 atomic ppm of halogen. More preferably, the second layer comprises 3-20 atomic % of arsenic, 0.1-20 atomic ppm of iodine and balance mainly consisting of selenium.

Photoconductive target of an image pickup tube and method for

A method of manufacturing a light sensitive heterodiode comprising an n-type transparent conductive layer and a p-type photoconductive layer provided thereon and forming rectifying contact therewith, in which before providing the p-type photoconductive layer on the n-type transparent conductive layer the surface of the latter is smoothed down by mechanical polishing or by bombarding it with ions accelerated by discharge.

Method of manufacturing light sensitive heterodiode

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Machida, Japan

Naohiro Goto