Heterogeneous FASnI3 Absorber with Enhanced Electric Field for High-Performance Lead-Free Perovskite Solar Cells

Nano-Micro Letters

Luis K. Ono¹  Yabing Qi¹  Guoqing Tong¹  Yiqiang Zhang²  Xiao Liu³  Hiroshi Segawa³  Liyuan Han⁴  Tianhao Wu⁴  Xinhui Luo⁴ 

[1]Energy Materials and Surface Sciences Unit (EMSSU), Okinawa Institute of Science and Technology Graduate University (OIST)

[2]School of Materials Science and Engineering, Henan Institute of Advanced Technology, Zhengzhou University

[3]Special Division of Environmental and Energy Science, Komaba Organization for Educational Excellence (KOMEX), College of Arts and Sciences, University of Tokyo

[4]State Key Laboratory of Metal Matrix Composites, School of Material Science and Engineering, Shanghai Jiao Tong University

关键词: Gradient FASnI3 absorber;    Built-in electric field;    Bulk charge recombination;    Lead-free perovskite solar cell;   

DOI  :  10.1007/s40820-022-00842-4

来源: DOAJ

【 摘 要 】

Abstract Lead-free tin perovskite solar cells (PSCs) have undergone rapid development in recent years and are regarded as a promising eco-friendly photovoltaic technology. However, a strategy to suppress charge recombination via a built-in electric field inside a tin perovskite crystal is still lacking. In the present study, a formamidinium tin iodide (FASnI3) perovskite absorber with a vertical Sn2+ gradient was fabricated using a Lewis base-assisted recrystallization method to enhance the built-in electric field and minimize the bulk recombination loss inside the tin perovskites. Depth-dependent X-ray photoelectron spectroscopy revealed that the Fermi level upshifts with an increase in Sn2+ content from the bottom to the top in this heterogeneous FASnI3 film, which generates an additional electric field to prevent the trapping of photo-induced electrons and holes. Consequently, the Sn2+-gradient FASnI3 absorber exhibits a promising efficiency of 13.82% for inverted tin PSCs with an open-circuit voltage increase of 130 mV, and the optimized cell maintains over 13% efficiency after continuous operation under 1-sun illumination for 1,000 h.

【 授权许可】

Unknown