Synthesis and characterization of Bi-doped antimony sulphide thin films for solar absorption applications.

Producing stable semiconducting thin films with low band gap energy by a viable technique is challenging for solar energy harvesting. Herein, Bi-doped Sb 2 S 3 thin films have been deposited on glass substrates by chemical bath deposition (CBD) technique followed by annealing at 400 °C. X-ray diffraction (XRD) patterns confirmed the orthorhombic phase of Sb 2 S 3 and successful incorporation of Bi+3 in the host lattice. Raman spectroscopy revealed the characteristic vibrational modes of Sb 2 S 3. Surface of films became smoother and compact with increasing Bi contents. Samples showed wide absorption range in the visible region. Band gap energy (E g) values were estimated using Tauc's relation and a blue shift in the absorption edge was observed with addition of Bi, thus E g increased from 1.58 to 1.71 eV. Higher values of absorption coefficient and absorption edge in the visible region suggest that the prepared Sb 2 S 3 thin films can be a right choice of an absorber layer. [Display omitted] • A novel approach for very smooth and large area thin films. • The deposited thin films show very high value of absorption coefficient, 4.0 x 10-4 cm-1. • The prepared thin films show excellent absorption in visible region. [ABSTRACT FROM AUTHOR]