| 摘要 |
PURPOSE:To improve the linearity of the output with respect to the amont of incident light, by making the optical forbidden band width of an i-type layer, which is virtually intrinsic, larger than that of an impurity layer. CONSTITUTION:An i-type layer 3i is provided in the center of a photoconductive film 3 which is sandwiched by first and second electrode films 2 and 4. Two n type impurity layers 3n1, 3n2 are respectively disposed on two main surfaces of the layer 3i. When the layer 3i is formed from. e.g., a(amorphous)-SixC1-x and the layers 3n1, 3n2 are formed from a-Si, the optical forbidden band width of the layer 3i becomes larger than that of the layers 3n1, 3n2 on account of the difference therebetween in terms of the film composition. Accordingly, when a bias is applied through lead members 5, 6, the forbidden band width difference acts so as to block carriers flowing in from the outside. In consequence, only a photocurrent in accordance with the amount of irradiation flows, and the linearity of the output with respect to the amount of incident light is improved. |
