Effect of source temperature on the electrical transport, microstructural and optical properties of tin monosulfide thin films prepared by close spaced sublimation method

摘要

Tin monosulfide (SnS) thin films were prepared by close spaced sublimation method at three different source temperatures of 550, 575 and 600°C. Structural, textural and compositional features were investigated by XRD, SEM, EDS and Raman spectroscopy. From absorption spectra, direct band gap increased from 1.18 to 1.23 eV with increasing source temperature. Electrical resistivity, Hall constant, carrier concentration and mobility values of the films prepared at source temperature of 600°C were 0.54 Ω.cm, 40.76 cm~3/C, 1.53x10~(17) and 75.48 cm~2/(V.s), respectively. The temperature-dependent conductivity was performed in the temperature range of 50-300 K. It was shown that three types of conduction mechanisms can be expected: thermionic emission passing through grain boundary at high temperature range (240-300 K), the Mott variable-range hopping (Mott-VRH) at low temperature range (135-235 K) and the Efros-Shklovskii variable-range hopping (ES-VRH) at very low temperature range (80-130 K).