Interface modification and performance optimization of SnO2 based perovskite solar cells

Abstract

Over the past decade, the power conversion efficiency of perovskite solar cells has increased from 3.8% to the current 25.5%, which is expected to become the next generation of commercial thin-film solar cells. However, the widely used TiO2 electron transport layer has low electron mobility, requires a high annealing temperature, and has poor UV light stability, limiting the performance of TiO2-based perovskite solar cells, especially long-term stability. SnO2 is expected to be the first choice to replace TiO2 electron transport layers because of its high electron mobility, suitable band structure, low-temperature solution synthesis, and stable chemical structure. Although the certified maximum efficiency of state-of-the-art SnO2-based perovskite solar cells had exceeded 25%, it was still below its theoretical efficiency. Therefore, component engineering, interface engineering, solvent engineering, and other methods to improve the efficiency and stability of SnO2-based perovskite solar cells have become a major research focus. Currently, regulating the SnO2/perovskite and perovskite/hole transport layer interface is key to optimizing the performance of SnO2-based perovskite solar cells. Most studies focused on improving the charge transport performance of SnO2 and modifying the SnO2/perovskite interface, while few studies have addressed defect passivation of the perovskite layer and the modification of the perovskite/SnO2 interface. Therefore, it is essential to summarize the research progress of interface modification and performance optimization of SnO2-based perovskite solar cells. This paper introduces the types and characteristics of defects in the bulk and surface of the SnO2 electron transport layer, as well as defects in the bulk, grain boundaries, and surface of the perovskite film. The research progress of the interface modification (bulk and surface defect passivation) and performance improvement for the SnO2 electron transport layer/perovskite and perovskite/hole transport layer are reviewed. Finally, the research directions of SnO2-based perovskite solar cells on interface modification and performance optimization are presented.

Keywords

• perovskite solar cells
• sno2
• defect passivation
• interface modification
• performance optimization