Optical and photoelectric properties of GaSe, InSe - semiconductor oxide of In, Sn, Ti, Bi, Zn, Cu, Cd heterojunctions

This paper examines the influence of constituent materials properties on the optical and photoelectrical characteristics of the heterojunctions. The edge of intrinsic absorption band of GaSe and InSe crystals, at the temperature of 78 K, consists of direct exciton bands from the states n=1 and n=2. Effective mass electron-hole pair in InSe is equal to 0.14 mo. Effective mass of electrons in p-GaSe is equal to 0.18 m o . Oxide-GaSe and oxide-GaSe heterojunctions were manufactured by thermal oxidation of In, Sn, Ti, Bi, Zn, Cu and Cd metallic films. The heterojunctions of GaSe and InSe semiconductors with studied oxides of metals reveal high photosensitivity in the visible and near IR spectrum. Photosensitivity band edge to low energies is determined by the GaSe or InSe band gap and the edge to high energy edge - by the respective oxides' gap. Free path of minority charge carriers in GaSe layer at the TiO 2 /GaSe:Cu, In 2 O 3 /InSe and TiO 2 /InSe heterojunction's interface depends on the fabrication technology and ranges between 0.56 μm÷1.97μm. The same parameter for structures based on InSe lies between 1,00÷3,45 μm for structures based on p-GaSe.