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US3939346A
Expired / Lapsed
US
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Gain photo-current enhancement method
Assignee: Xerox Corp
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Filing: 1974-09-18
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Granted: 1976-02-17
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Expires: 1994-09-18
Abstract
Abstract High quantum yields of gain photocurrent provided by sandwiching an insulating layer in contact with a photoconductor between two electrodes, applying an electrical potential thereacross, and directing excitation light upon the photoconductor are increased by simultaneously impinging the photoconductor with infrared radiation during exposure to the excitation light where the photoconductor comprises selenium or a selenium alloy. In cyclical operation of gain photocurrent devices having a photoconductive layer comprising selenium or a selenium alloy, fatigue effects are overcome by irradiation with infrared radiation.
Inventors
- 👤 Simpei Tutihashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:09
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/36; H01J29/39; H01J29/45; H10; H10F; H10F71/00
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
97 words
The method of providing gain photocurrent, comprising: a. providing between two electrodes, an insulating layer in contact with a photoconductive layer comprising selenium or selenium alloy, the thickness ratio of photoconductive layer to insulating layer being at least about 10 to 1; b. applying a D.C. voltage across said photoconductive and insulating layers; c. impinging said photoconductive layer with light having a wavelength within the fundamental absorption band of the selenium or selenium alloy within said photoconductive layer and which excites a primary current within said photoconductive layer; and d. impinging said photoconductive layer with infrared radiation.
Claim 2
Independent Claim
97 words
The method of providing gain photocurrent, comprising: a. providing between two electrodes, an insulating layer in contact with a photoconductive layer comprising selenium or selenium alloy, the thickness ratio of photoconductive layer to insulating layer being at least about 10 to 1; b. applying a D.C. voltage across said photoconductive and insulating layers; c. impinging said photoconductive layer with light having a wavelength within the fundamental absorption band of the selenium or selenium alloy within said photoconductive layer and which excites a primary current within said photoconductive layer; and d. impinging said photoconductive layer with infrared radiation.
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein said insulating layer comprises an insulating material having an ionization potential less than about 8 eV.
Claim 4
Dependent Claim
24 words
The method of claim 1 wherein at least one of said electrodes comprise a material having a work function greater than about 4.5 eV.
Claim 5
Dependent Claim
16 words
The method of claim 3 wherein said at least one electrode is adjacent said insulating layer.
Claim 6
Dependent Claim
28 words
The method of claim 4 wherein said at least one electrode comprises a material selected from the group consisting of platinum, copper, gold, tin oxide, and indium oxide.
Claim 7
Dependent Claim
25 words
The method of claim 2 wherein said insulating layer comprises an insulating mateiral selected from the group consisting of phenoxy resin, poly(2-propeneanthracene), poly(2-vinyl-anthracene) and poly[1-(2-antrile)ethylmethylacrylate].
Claim 8
Dependent Claim
25 words
The methord of claim 1 wherein the step of impinging said photoconductive layer with infrared radiation is performed simultaneously with the performance of step (c).
Claim 9
Dependent Claim
12 words
The method of claim 1 wherein said photoconductive layer comprises arsenic triselenide.
Claim 10
Dependent Claim
18 words
The method of claim 8 wherein said infrared radiation has a wavelength from about 7000A to about 8500A.
Claim 11
Dependent Claim
24 words
The method of claim 9 wherein said infrared radiation has an intensity of from about 10 14 to about 10 16 photons/cm 2 -sec.
Claim 12
Dependent Claim
25 words
The method of claim 10 wherein said infrared radiation impinges said photoconductive layer for a period of time from about 0.1 to about 20 seconds.
Claim 13
Dependent Claim
32 words
The method of claim 1 further including the step of removing the voltage applied in step (b) subsequent to the performance of step (c) and prior to the performance of step (d).
Claim 14
Dependent Claim
41 words
The method of claim 1 wherein the performance of said step (d) is continuously performed over a predetermined period of time, further including, during said predetermined period of time the performance of steps (a), (b) and (c) at least one time.
Claim 15
Dependent Claim
40 words
The method of claim 13 wherein said predetermined period of time is sufficient for the performance of steps (a) through (c), in sequence, at least twice; further including the performance of steps (a) through (c), in turn, at least twice.
Claim 16
Independent Claim
123 words
The method of imaging comprising: a. providing between two electrodes a photoconductive layer comprising selenium or a selenium alloy and sandwiched between an insulating layer and an imaging layer, the ratio of photoconductive layer thickness to insulating layer thickness being at least about 10 to 1, said imaging layer comprising material having at least one optical property which undergoes change when said material is subjected to an applied voltage. b. applying a D.C. voltage across said insulating, photoconductive and imaging layers; c. impinging imagewise said photoconductive layer with light having a wavelength within the absorption band of photoconductive material within said photoconductive layer and for a period of time wherein gain photocurrent is obtained; and d. impinging said photoconductive layer with infrared radiation.
Claim 17
Independent Claim
123 words
The method of imaging comprising: a. providing between two electrodes a photoconductive layer comprising selenium or a selenium alloy and sandwiched between an insulating layer and an imaging layer, the ratio of photoconductive layer thickness to insulating layer thickness being at least about 10 to 1, said imaging layer comprising material having at least one optical property which undergoes change when said material is subjected to an applied voltage. b. applying a D.C. voltage across said insulating, photoconductive and imaging layers; c. impinging imagewise said photoconductive layer with light having a wavelength within the absorption band of photoconductive material within said photoconductive layer and for a period of time wherein gain photocurrent is obtained; and d. impinging said photoconductive layer with infrared radiation.
Claim 18
Dependent Claim
11 words
The method of claim 15 wherein said imaging layer is photochromic.
Claim 19
Dependent Claim
29 words
The method of claim 15 wherein said impinging layer comprises a material selected from the group consisting of nematic liquid crystalline materials, cholesteric liquid crystalline materials and mixtures thereof.
Claim 20
Dependent Claim
23 words
The method of claim 17 wherein said imaging layer comprises about 80% by weight p-methoxy-benzilidene-p-nbutylaniline and about 20% by weight cholesterol oleyl carbonate.
Claim 21
Dependent Claim
12 words
The method of claim 15 wherein said photoconductive layer comprises arsenic triselenide.
Claim 22
Dependent Claim
24 words
The method of claim 19 wherein the electrode adjacent the insulating layer comprises a material having a work function greater than about 4.5 eV.
Claim 23
Dependent Claim
29 words
The method of claim 20 wherein the electrode adjacent the insulating layer comprises a material selected from the group consisting of platinum, copper, gold, tin oxide and indium oxide.
Claim 24
Dependent Claim
18 words
The method of claim 20 wherein said insulating layer has an ionization potential less than about 8 eV.
Claim 25
Dependent Claim
21 words
The method of claim 20 wherein said infrared radiation comprises radiation having a wavelength from about 7000 to about 8500 A.
Claim 26
Dependent Claim
23 words
The method of claim 23 wherein said infrared radiation has an intensity of about 10 14 to about 10 16 photons/cm 2 -sec.
Claim 27
Dependent Claim
25 words
The method of claim 24 wherein said infrared radiation impinges said photoconductive layer for a period of time from about 0.1 to about 20 seconds.
Claim 28
Dependent Claim
30 words
The method of claim 15 further including the step of removing the voltage applied in step (b) subsequent to performance of step (c) and prior to performance of step (d).
Claim 29
Dependent Claim
17 words
The method of claim 15 wherein said step (d) is performed simultaneously with the performance step (c).
Claim 30
Dependent Claim
68 words
The method of claim 15 wherein in step (c) said light impinging said photoconductive layer comprises light from at least two sources, at least one of which is in imagewise configuration, the superimposition of the light from one source with that from the other source being sufficient to substantially immediately initiate gain photocurrent, and the light from each source along being insufficient to substantially immediately initiate gain photocurrent.
Claim 31
Dependent Claim
41 words
The method of claim 15 wherein the performance of said step (d) is continuously performed over a predetermined period of time, further including, during said predetermined period of time the performance of steps (a), (b) and (c) at least one time.
Claim 32
Dependent Claim
40 words
The method of claim 29 wherein said predetermined period of time is sufficient for the performance of steps (a) through (c), in sequence, at least twice; further including the performance of steps (a) through (c), in turn, at least twice.
References Cited (Backward Citations)
US3069551A
Cited
US3732429A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-02-16 | 1979-08-18 | 1980-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-16 | 1983-08-18 | 1984-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-16 | 1987-08-18 | 1988-02-17 | $7700.00 | Window Closed / Lapsed |