摘要
Lead-free tin perovskite solar cells(PSCs)have undergone rapid development in recent years and are regarded as a promising ecofriendly 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(FASnI;)perovskite absorber with a vertical Sn;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 Sn;content from the bottom to the top in this heterogeneous FASnI;film,which generates an additional electric field to prevent the trapping of photo-induced electrons and holes.Consequently,the Sn;-gradient FASnI;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.
基金
This work was supported by the National Natural Science Foundation of China(Grant Nos.11834011 and 12074245)
The work performed at the University of Tokyo was supported by JSPS KAKENHI Grant Number 21H02040 and the New Energy and Industrial Technology Development Organization(NEDO)
T.W.,G.T.,L.K.O.,and Y.B.Q.acknowledge the support from the Energy Materials and Surface Sciences Unit of the Okinawa Institute of Science and Technology Graduate University.We thank Mrs Miwako Furue and Dr.Haibin Wang at the University of Tokyo for the GIXRD and EDS measurements
Open access funding provided by Shanghai Jiao Tong University
