2021/07/26 by Sofiia Kosar, Kosar, Sofiia, Andrew Winchester +21 · 1 citation
Engineering · Materials Science · #Applied Physics (physics.app-ph) #Chalcogenide Semiconductor Thin Films #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Optics (physics.optics) #Perovskite Materials and Applications #Quantum Dots Synthesis And Properties
paper · pdf · doi:10.48550/arxiv.2107.12572
openalex publication_date 2021/07/26 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28
With rapidly growing photoconversion efficiencies, hybrid perovskite solar\ncells have emerged as promising contenders for next generation, low-cost\nphotovoltaic technologies. Yet, the presence of nanoscale defect clusters, that\nform during the fabrication process, remains critical to overall device\noperation, including efficiency and long-term stability. To successfully deploy\nhybrid perovskites, we must understand the nature of the different types of\ndefects, assess their potentially varied roles in device performance, and\nunderstand how they respond to passivation strategies. Here, by correlating\nphotoemission and synchrotron-based scanning probe X-ray microscopies, we\nunveil three different types of defect clusters in state-of-the-art triple\ncation mixed halide perovskite thin films. Incorporating ultrafast\ntime-resolution into our photoemission measurements, we show that defect\nclusters originating at grain boundaries are the most detrimental for\nphotocarrier trapping, while lead iodide defect clusters are relatively benign.\nHexagonal polytype defect clusters are only mildly detrimental individually,\nbut can have a significant impact overall if abundant in occurrence. We also\nshow that passivating defects with oxygen in the presence of light, a\npreviously used approach to improve efficiency, has a varied impact on the\ndifferent types of defects. Even with just mild oxygen treatment, the grain\nboundary defects are completely healed, while the lead iodide defects begin to\nshow signs of chemical alteration. Our findings highlight the need for\nmulti-pronged strategies tailored to selectively address the detrimental impact\nof the different defect types in hybrid perovskite solar cells.\n