JPS6410660A - Photoelectric conversion device - Google Patents

Abstract

PURPOSE:To obtain a photoelectric conversion signal with little irregularity, by stabilizing electrically a surface layer in which surface recombination current generates, by arranging a stabilizing electrode on a surface on which a semiconductor region is formed. CONSTITUTION:In the title photoelectric conversion device, it is utilized that recombination current depends on a surface potential, and a stabilizing electrode 11 to control the electric potential of a silicon surface is provided. The electrode 11 is formed on the surface of a p-base region 6 and an N<-> collector region 2 on the periphery of the region 6, and made of transparent electrode material such as ITO and SnO2. In the non-controlled state where no voltage is applied to the electrode 11, a dark current largely changes according to external disturbance. When the surface potential is stabilized by keeping at a control potential less than or equal to -1V, the dark current is restricted within a small range. By operating the device in this state, a read-out signal with little irregularity can be stably output, In the case where the electrode is not kept at a constant potential and put in a floating state, the silicon surface can be sufficiently stabilized against external potential disturbance, by making the electrode area sufficiently large as compared with the cell area.