Annealing temperature effects on optical and photoelectric properties of sputtered indium-doped PbSe thin films

Abstract

Indium-doped PbSe thin films deposited on Si(111) by magnetron sputtering were annealed at different temperatures and characterized using the X-ray diffraction, Fourier transform infrared spectroscopy and physical properties measurement system. After the annealing treatment, an oxidation layer containing PbSe, PbO, SeO2 and In2Se3 is formed on the film surface. The optical band gap of the annealed samples increases to a maximum of 0.276 eV at 150 °C, and then decreases with the annealing temperature due to the position shift of the valence band maximum and the conduction band minimum. The photoelectric sensitivity of the annealed indium-doped PbSe thin films increases by 1.5–2 times, compared with the untreated samples. Moreover, the average value of the resistance change rate increases almost linearly with the annealing temperature due to the concentration of the dark charge carriers increases with the annealing temperature confirmed by the Hall effect measurements.