Electric Field Analysis of the ITO-ZnSe-CdTe Photo Sensor Cell

Abstract

In this report, the ITO-ZnSe-CdTe cell and the ITO-ZnSe-CdTe-ZnTe cell as a photo sensor were analyzed comparatively with the use of the electric field analysis from spectral sensitivity data. From analysis, it is presumed that there is the depletion layer from the junction surface to 0.194μm in zone of CdTe layer at the ITO-ZnSe-CdTe cell. On the other hand, the ITO-ZnSe-CdTe-ZnTe cell has the depletion layer in whole region of CdTe layer. It is presumed that both ZnSe layer and ZnTe layer form the depletion layer of CdTe layer in the ITO-ZnSe-CdTe-ZnTe cell. The CdTe layer, which has 0.8μm in thickness, absorbs all of visible wavelengths, and both of two cells have CdTe layer 0.8μm in thickness. Luminous sensitivity of the ITO-ZnSe-CdTe cell is much less than luminous sensitivity of the ITO-ZnSe-CdTe-ZnTe cell. It is presumed that differences of the luminous sensitivity between those two cells arise from differences of the electric field distribution. From this analysis, it is presumed that the structure of ZnSe-CdTe-ZnTe makes depletion layer in whole region of CdTe layer.