Gain photo-current enhancement method
AssigneeXerox Corporation
InventorSimpei Tutihashi
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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.
Claims30
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.
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.
Dependencies are inferred from the claim text.