Review on optical, structural and electrical properties of ZnTe thin films: effect of deposition techniques, annealing and doping

Abstract

Zinc Telluride (ZnTe) has become a very fascinating research material for the scientists over past many years. This p type semiconducting material has a wide band gap, which makes it useful in many optoelectronic applications such as solar cells, light emitting diodes, laser screens etc. With the desire for eco-friendly alternative energy resources, it excites to investigate potential semiconducting materials at nano scale for solar cell applications. Due to direct, wide and controllable optical band gap of ZnTe with easy doping makes it a potential material for photoelectrochemical applications. In the present work, an attempt has been made to compile the work done by various researchers on optical properties (band gap, refractive index and absorption/transmission spectra, etc.), structural properties (crystallite/grain size, lattice constant and Zn:Te, etc.) and electrical properties (resistivity, activation energy, carrier concentration and hall mobility, etc.) of ZnTe thin films with main emphasis on the effect of deposition techniques, doping and annealing on these properties. Most of the thin films reported in literature shown polycrystalline cubic structure. It is found that annealed ZnTe thin films show enhanced optical, structural and electrical properties at different annealing temperatures. Doping methods used by various researchers have been discussed in detail and results show good doping impact on these properties as well.