Evaporation-Controlled Spray Deposition Process Achieving Ultrasmooth Photoactive Layer for Efficient Organic Solar Cells

More focus has been placed in recent years on the most promising Sb2(S, Se)3. Because of its black-box character, the hydrothermal process has drawbacks, such as difficulties managing variables like pH, temperature, and chemical reactions. To overcome these challenges, a monitored and straightforward solution process was developed, enabling the wide-scale production of Sb2(S, Se)3 devices. This study carefully examined the impact of Sb2(S, Se)3 absorber thickness on the performance of photovoltaic devices. By effectively suppressing the recombination of chargest the Sb2(S, Se)3/CdS interface and reducing interfacial and bulk defects, a carefully managed optimum thickness improved the device's carrier transport mechanism. We found that solar cells with a light absorber thickness of approximately 210 nm had a smaller Urbach energy compared to solar cells with a thickness of approximately 95 nm, indicating a lower number of defect states. Additionally, the concentration of bulk and interface defects was lower in solar cells with a thickness of approximately 210 nm compared to those with a thickness of approximately 95 nm. Thus, a Sb2(S, Se)3 device with about 210 nm thick light absorber exhibited high efficiency of 5.51%, indicating a thickness-controlled CBD process with great potential to design a high-performance solar cell.