Cage Polyamine Molecule Hexamethylenetetramine as Additives for Improving Performance of Perovskite Solar Cells

摘要

As a rising star in the photovoltaic field, perovskite solar cells (PSCs) have attracted extensive attention. However, the industrialization development of PSCs still faces the dual challenges of improving efficiency and stability. Herein, a cage polyamine molecule hexamethylenetetramine (HMTA) as additive is incorporated into the tin oxide electron transport layer (ETL). The introduction of HMTA improves the electron extraction ability of SnO2 and optimizes the energy-level alignment of function layers. The modification of HMTA also passivates the uncoordinated Pb~(2+) in the perovskite and reduces the oxygen vacancy deffects of SnO2, which alleviate trap-state density and carrier nonradiative recombination. As a result, the PSC based on the SnO2 ETL modified with HMTA achieves a high power conversion efficiency of 22.37 along with good stability. The research results demonstrate a typical case of using cage polyamines to improve the performance and stability of PSCs.