Low Sb–O Content Sb₂S₃ Thin Films via a Nonaqueous-Based Chemical Bath Deposition for Efficient Indoor Sb₂S₃ Solar Cells

In this paper, the low Sb–O content Sb 2 S 3 thin films were successfully prepared by a nonaqueous-based chemical bath deposition method with SbCl 3 as the Sb source, thioacetamide as the S source, and DMF as the solvent. The defect state density of the resulting low Sb–O content Sb 2 S 3 thin films can be regulated by the annealing process. The influence of the annealing process on the crystalline phase, absorbance, microstructure, defect state density of the Sb 2 S 3 thin film, and photovoltaic performance of the corresponding solar cells was systematically investigated. The results revealed that the Sb 2 S 3 thin films with the annealing process of 150 °C for 30 min and then 320 °C for 10 min exhibit higher crystallinity, optimal orientation of the (hk1) planes, and lower density of trap states, and the corresponding solar cells achieved a photoelectric conversion efficiency (PCE) of 5.64%. At the same time, anatase TiO 2 nanorod arrays with higher electron mobility were successfully obtained by increasing the annealing temperature to 600 °C of the hydrothermal TiO 2 nanorod arrays. The PCE of the Sb 2 S 3 solar cells with anatase TiO 2 nanorod arrays increased to 6.97%. Using the light-emitting diode (LED) with color temperatures of 2762 and 6301 K, under an illuminance of 1000 lx, the Sb 2 S 3 indoor solar cells exhibit the PCE of 16.99% and 15.40%, respectively.