Park Minji, Lim Chanwoo, Lee Hyejin, Kang Byungsoo, Hwang Hyun Wook, Kim Seok Ki, Lee Phillip, Kim Woong, Yu Hyeonggeun, Kim Taehee
Advanced Photovoltaics Research Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea.
Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea.
ACS Appl Mater Interfaces. 2024 Jun 26;16(25):32375-32384. doi: 10.1021/acsami.4c04128. Epub 2024 Jun 13.
Colloidal PbS quantum dot solar cells (QDSCs) have been primarily demonstrated in n-i-p structures by incorporating a solution-processed ZnO electron transporting layer (ETL). Nevertheless, the inherent energy barrier for the electron extraction at the ZnO/PbS junction along with the defective nature significantly diminishes the performance of the PbS QDSCs. In this study, by employing Sn-doped ZnO (ZTO) ETL, we have tuned the conduction band offset at the junction from spike-type to cliff-type so that the electron extraction barrier can be eliminated and the overall photovoltaic parameters can be enhanced (open-circuit voltage of 0.7 V, fill factor over 70%, and efficiency of 11.3%) as compared with the counterpart with the undoped ZnO ETL. The X-ray photoelectron spectroscopy (XPS) analysis revealed a mitigation of oxygen vacancies in the ZTO ETL of our PbS QDSCs. Our work signifies the importance of Sn doping into the conventional ZnO ETL for the superior electron extraction in PbS QDSCs.
通过引入溶液处理的ZnO电子传输层（ETL），胶体硫化铅量子点太阳能电池（QDSC）主要在n-i-p结构中得到了展示。然而，ZnO/PbS结处电子提取的固有能垒以及缺陷性质显著降低了PbS QDSC的性能。在本研究中，通过采用掺锡的ZnO（ZTO）ETL，我们将结处的导带偏移从尖峰型调整为悬崖型，从而消除了电子提取势垒，并提高了整体光伏参数（开路电压为0.7 V，填充因子超过70%，效率为11.3%），与未掺杂ZnO ETL的对应器件相比有了提升。X射线光电子能谱（XPS）分析表明，我们的PbS QDSC的ZTO ETL中的氧空位有所减少。我们的工作表明了在传统ZnO ETL中掺锡对于PbS QDSC中优异电子提取的重要性。
