Optical and electrical properties of thermally evaporated In10 Se90 and In24Se76 films

Inx Se100−x thin films with (x=10 and 24) were deposited on glass substrates by thermal evaporation. Current density—voltage measurements were carried out to determine the electrical properties of these films. At low voltage, the current in the forward direction varied exponentially with voltage. At higher voltages, two distinct regions of ohmic and space-charge-limited conduction (SCLC) under forward bias were observed. The square power dependence in (SCLC) indicated that current conduction is limited by a discrete trapping level above the valence band edge. The results yielded-total trap concentration Nt, and trap energy Et, barrier height ϕb, trapping factor θ and concentration of the free carriers n0. Optical and absorption behavior of these thin films were studied from, the reflection and transmission. Optical band gap was determined and arose from indirect transitions. The value of the optical band gap was found to decrease with the increasing In content in Inx Se100−x.