PHOTODETECTOR WITH ENHANCED RESPONSIBILITY

PROBLEM TO BE SOLVED: To provide a photodetctor whose response speed for a input light signal is enhanced more and its responsibility is increased, and to provide a method for efficiently manufacturing these photodetectors. SOLUTION: The photodetector includes a high indium concentration (H-I-C) absorption layer of a group III sublattice indium concentration of not less than 53%. The H-I-C absorption layer has an enhanced responsibility, without decreasing the band width. The photoelectric conversion structure, containing the H-I-C absorption layer, employs a transformation buffer layer, by forming a lattice constant gradient between the photoelectric conversion structure and a substrate, so that the desired kind of substrate can be formed. The responsibility of the photodetector can be further improved by constructing the photodetector so that an incident light signal passes the H-I-C absorption layer at least two times. COPYRIGHT: (C)2005,JPO&NCIPI