Single-crystal thin film InP: Fabrication and absorption measurements

Abstract

A new process for separating high quality single-crystal InP thin films from the growth substrate is reported. These thin films were used for transmission measurements to determine InP absorption coefficients above the band edge. Photoluminescence measurements performed on these films before and after the fabrication process verified that the high quality of the separated thin film was not affected by the fabrication process. Two n-type InP thin films, one with a doping concentration of 1.4×1017 cm−3 (1 μm thick) and the other with a doping concentration of 3.2×1018 cm−3 (2.5 μm thick), were grown and subsequently separated from the substrate. Using these separated films, the first direct transmission measurements of above band edge absorption coefficients in doped InP films are reported in this letter.