Achieving Low VOC-deficit Characteristics in Cu2ZnSn(S,Se)4 Solar Cells through Improved Carrier Separation

• DOI: 10.1021/acsami.0c16936
• Publication Date: 2021-01-04T16:24:01Z
• Authors: Vijay Karade; Eunyoung Choi; Myeng Gil Gang; Hyesun Yoo; Abhishek Lokhande; Pravin Babar; Jun Sung Jang; Jan Seidel; Jae Sung Yun; Jongsung Park; Jin Hyeok Kim
• Keywords: Kesterite; Open-circuit voltage

Kesterite-based thin-film solar cells (TFSCs) have recently gained significant attention in the photovoltaic (PV) sector for their elemental earth abundance and low toxicity. An inclusive study from past reveals basic knowledge about grain boundary (GB) interior (GI) interface. However, compositional dependency of surface potential within GBs GIs remains unclear. The present work provides insights into bulk GB interfaces. tin (Sn) composition is sensitive to absorber morphology, therefore, it significantly impacts device properties. morphology improves with formation larger grains as Sn content increases. Additionally, presence Sn(S,Se)2 increased [ZnCu + VCu] A-type defect cluster density are observed, validated through Raman analysis. secondary ion mass spectroscopy analysis altered distribution sulfur (S) sodium (Na) higher near-surface accumulation. synergistic outcome defects accumulation S near interface a GI difference expedites carrier separation improvement. Consequently, at an optimum ratio Cu/(Zn+Sn) = ∼0.6, power conversion efficiency (PCE) improved 6.42 11.04% record open-circuit voltage (VOC) deficit 537 mV.