Performance Of Perovskite Solar Cells Based On Single Crystal Engineering

Inorganic–organic metal halide hybrid perovskites have gained significantly attention due to its good semiconducting properties including high absorption coefficient,long carrier lifetime,and satisfactory carrier mobility.Thus,inorganic–organic hybrid perovskites have become one of the most promising materials for optoelectronic devices such as solar cells,photodetectors,LED,etc.In the past several years,although the power conversion efficiency（PCE）of perovskites has grown rapidly over 23%from the initial 3.8%in 2009.However,due to the initial sensitivity of perovskite to air,perovskite thin films and devices are easily decomposed when prepared or stored in humid air,so the development of perovskite cloth solar cells is still limited.In order to improve these problems,this paper focus on the synthesis of single crystal doped PEA⁺to improve the conversion efficiency of perovskite solar cells.The photoelectric performance difference of films and devices was also studied by comparing with the conventional molecular/ion precursor-solution-mixing methods and the relevant experimental contents and research results are as follows:（1）We developed a facile method for PEA⁺doping MA_1-xPEA_xPbI₃ perovskite single crystal for first time and then dissolved above single crystal to prepare a precursor solution.With the air-processed,highly crystalline、lower trap density and large grain size（over 6.6times bigger than that from control films by conventional method）perovskite films were gained.（2）The effects of PEA⁺concentration on the photoelectric conversion performance and stability of perovskite solar cells was studied.The concentration of PEA⁺was 0,0.05,0.1,0.15,0.2 respectively.With the optimal doping concentration of 0.1,the conversion efficiency of perovskite solar cells was increased from 15.6%（traditional solution method）to 17.6%（single crystal engineering）.（3）Furthermore,benefiting from the high moisture resistance of PEA⁺doping and single crystal engineering,the moisture stability of resulted perovskite solar cells also is improved significantly.The PEA⁺doped MA_0.9PEA_0.1PbI₃ single crystal engineering based perovskite solar cells without any encapsulation retain 75%of the initial performance after 30 days storage in ambient air under a relative humidity of 50%,and 2times faster degradation rate is observed for control,conventional,solution-mixing based,doped perovskite solar cells when compared with single crystal engineering based ones.