Microstructural, Optical, and Electrical Properties of Chemically Deposited Tin Antimony Sulfide Thin Films for Use in Optoelectronic Devices

Abstract

The influence of different tin‐amount on the properties of chemically deposited tin antimony sulfide (TAS) thin films is explored, to establish their suitability in thin‐film solar‐cell devices. X‐ray diffraction studies reveal single phase without the presence of other binaries. Energy dispersive X‐ray spectroscopy (EDS) indicates Sn‐rich behavior, which is confirmed by X‐ray photoelectron spectroscopy (XPS) analysis. The crystallite size is between 28.4 and 40.5 nm, typically exhibiting an increase up to 0.012 mol of the Sn‐amount and then decrease marginally. Scanning electron microscopy (SEM) images reveal leaf‐like structures. The transmittances decrease with increasing tin‐amount; the optical absorption coefficient is >104 cm−1; the energy bandgap is direct, and varied in the range 1.22–1.50 eV. The refractive index lies between 2.51 and 4.11, whereas the dielectric constants range from 7.49 to 20.1. The carrier mobility is between 18.5 and 46.8 cm2 V−1s−1. The bulk resistivity is found to vary between 5.71 × 104 and 1.47 × 105 Ω cm, with lower values obtained at ≥0.012 mol of the Sn‐amount. Hall effect measurements indicate that the TAS thin films exhibit p‐type electrical conductivity. These values fulfill excellent absorber layer requirements in thin‐film solar‐cell devices.