N, N-Dimethylformamide Solvent-Assisted Hydrothermal Deposition for Semitransparent Sb2(S, Se)3 Solar Cells

Abstract

Antimony selenosulfides (Sb₂(S, Se)₃) has garnered significant attention due to its exceptional optoelectronic properties. The quality of the Sb₂(S, Se)₃ thin film is pivotal for its role as the light-absorbing layer in solar cells and directly impacts device performance. This study depicts for the first time the use of N, N-dimethylformamide as an assisting solvent in the hydrothermal deposition process for producing semitransparent solar cells based on Sb₂(S, Se)₃ thin films. Comparative analysis with the traditional hydrothermal deposition method using water as the sole solvent reveals a substantial reduction in surface pinholes of the Sb₂(S, Se)₃ thin film, thereby mitigating current leakage resulting from direct contact between the electron transport layer and electrode. X-ray diffraction characterization demonstrates enhanced crystallinity with [021] orientation in the improved Sb₂(S, Se)₃ thin film, facilitating improved carrier transport. Furthermore, the dark J–V curve reveals that the reverse saturation current of the Sb₂(S, Se)₃ solar cell with the traditional hydrothermal method is 3.45 x 10^-6 mA/cm², whereas for the enhanced Sb₂(S, Se)₃ solar cell, it is 4.65 x 10^-7 mA/cm², indicating reduced carrier trapping by defects. These findings reveal that the fill factor of devices obtained through solvent-assisted hydrothermal deposition method with N, N-dimethylformamide as an assisting solvent increased from 35.06% to 40.96% and achieved the power conversion efficiency of 3.23%, representing a 50% improvement of the power conversion efficiency over those obtained through traditional hydrothermal deposition without any assisting solvent. The average visible light transmittance was about 9.17%.