ELECTRICAL AND PHOTOELECTRIC PROPERTIES OF PbGa_2Se_4 SINGLE CRYSTALS

摘要

The dark current ,spectral response of photocurrent, and thermal quenching of photocurrent were studied in PbGa_2Se_4 single crystals grown by the Bridgman-Stockbarher technique. Measurements were performed on 50- to 200-μm In-PbGa_2Se_4In sandwich　structures in electric fields from to*3×10~4 V/cm at temperatures from 200 to 400 K.The spectral response of the photocurrent through PbGa_2Se_4 showed maxima at 530,760,and 1000 nm.The band gap of PbGa_2Se_4,Eg=2.35 eV, was found from the short-wavelength maximum by the Moss rule. As the electric field rose to 10~4 V/cm, the maximum photocurrent increased by two orders of magnitude. From thermal quenching of photocurrent, the ionization energy of recombination centers was found to be 0.89 eV.