Patent ID: 8378444
Filing Date: 2013-02-19
Classification: H01L,Y02E

Abstract:
1. A photodiode comprising: a light-absorbing layer composed of a compound-semiconductor film of chalcopyrite structure, the compound-semiconductor film of chalcopyrite structure being made of Cu (Inx, Ga1-x) Se2 (0≦x≦1); a surface layer disposed on the light-absorbing layer, the surface layer having a higher band gap energy than the compound-semiconductor film; an upper electrode layer disposed on the surface layer; and a lower electrode layer disposed on a backside of the light-absorbing layer in opposition to the upper electrode layer, wherein the upper electrode layer and the lower electrode layer have a reverse bias voltage applied in between to detect electric charges produced by photoelectric conversion in the compound-semiconductor film of chalcopyrite structure, wherein the surface layer has a lower Cu concentration than the compound-semiconductor film made of Cu (Inx, Ga1-x) Se2 (0≦x≦1), and a particle size of the surface layer is smaller than that of the compound-semiconductor film of chalcopyrite structure.