Crystal Growth Promotion and Defects Healing Enable Minimum Open‐Circuit Voltage Deficit in Antimony Selenide Solar Cells

• Published in: Advanced science Vol. 9; no. 9; pp. e2105142 - n/a
• Main Authors: Liang, Guangxing, Chen, Mingdong, Ishaq, Muhammad, Li, Xinru, Tang, Rong, Zheng, Zhuanghao, Su, Zhenghua, Fan, Ping, Zhang, Xianghua, Chen, Shuo
• Format: Journal Article
• Language: English
• Published: Germany John Wiley & Sons, Inc 01.03.2022; Wiley Open Access; John Wiley and Sons Inc; Wiley
• Subjects: absorber layer engineering; Cadmium telluride; Chemical Sciences; crystal growth; defects healing; Efficiency; Engineering; Grain size; Heat; Interfaces; open‐circuit voltage deficit; Photovoltaic cells; Sb2Se3 solar cells; Thin films; open-circuit voltage deficit; absorber layer engineering; crystal growth; defects healing; Sb2Se3 solar cells
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202105142

Antimony selenide (Sb2Se3) is an ideal photovoltaic candidate profiting from its advantageous material characteristics and superior optoelectronic properties, and has gained considerable development in recent years. However, the further device efficiency breakthrough is largely plagued by severe open‐circuit voltage (VOC) deficit under the existence of multiple defect states and detrimental recombination loss. In this work, an effective absorber layer growth engineering involved with vapor transport deposition and post‐selenization is developed to grow Sb2Se3 thin films. High‐quality Sb2Se3 with large compact crystal grains, benign [hk1] growth orientation, stoichiometric chemical composition, and suitable direct bandgap are successfully fulfilled under an optimized post‐selenization scenario. Planar Sb2Se3 thin‐film solar cells with substrate configuration of Mo/Sb2Se3/CdS/ITO/Ag are constructed. By contrast, such engineering effort can remarkably mitigate the device VOC deficit, owing to the healed detrimental defects, the suppressed interface and space‐charge region recombination, the prolonged carrier lifetime, and the enhanced charge transport. Accordingly, a minimum VOC deficit of 0.647 V contributes to a record VOC of 0.513 V, a champion device with highly interesting efficiency of 7.40% is also comparable to those state‐of‐the‐art Sb2Se3 solar cells, paving a bright avenue to broaden its scope of photovoltaic applications. A two‐step thermodynamic/kinetic deposition process involving vapor transport deposition and post‐selenization is developed to grow high‐quality Sb2Se3 thin films. Such absorber engineering can heal detrimental defects, prolong carrier lifetime, suppress interface, and space‐charge region recombination. Thus, the substrate structured Mo/Sb2Se3/CdS/ITO/Ag solar cell delivers a record open‐circuit voltage (VOC) of 0.513 V with minimum deficit, and highly competitive efficiency of 7.40%.