Structural, optical and electrical properties of Sb2Te3 films prepared by pulsed laser deposition

Sb2Te3 films were deposited using pulsed laser deposition technique onto substrates heated up to different temperatures. According to X-ray diffraction analysis, the films were well crystallized with preferred orientation of (00l), and belong to the rhombohedral structure. Raman spectrum explained the change of microstructure by the lattice vibration modes, revealing the dependent relationship between the nucleation rate and substrate temperatures. The scanning electron microscope images exhibit uniform and smooth films surface morphologies. Additionally, the absorption coefficient of the film is above 104 cm−1 in the infrared range and the corresponding optical band gap is around 0.32 eV. The resistivity of the films decreases as the substrate temperature increases, and the temperature coefficient of resistance for Sb2Te3 films is 0.15% K−1. These results imply that Sb2Te3 films have a potential application for uncooled infrared detection.