Structural, optical and electrical properties of vacuum evaporated PbSe/ZnSe multilayer thin films

Abstract

Multilayer thin films structures have received wide-spread attention due to their fast response and high efficiency. In this paper, we report the properties of PbSe/ZnSe multilayer thin films prepared by vacuum evaporation technique by sequential deposition of individual compounds. The prominent peak corresponding to (2 0 0) plane was observed in the Xray diffractogram with cubic crystal structure. The size of the crystallites are found to be 8 nm and 14 nm for the three-layer and five-layer films respectively. The absorption edge starts at 430 nm for the three-layer structures while that for the fivelayer film starts at 480 nm. The calculated optical band gaps of the three-layer and five-layer PbSe/ZnSe multilayer films are found to be 1.7 eV and 1.9 eV respectively. The electrical resitivities are found to be 2.8 × 107 Ω-cm for the three-layer film and 1.02 Ω cm for the five-layer film. The various electrical properties of the films such as mobility, carrier concentration and sheet resistance also are discussed in this paper.