An efficient, flexible perovskite solar module exceeding 8% prepared with an ultrafast PbI2 deposition rate

Kunpeng Li,Yibing Cheng,Junyan Xiao,Wangnan Li,Peng Zhou,Jie Zhong,Fuzhi Huang,Yangwen Zhang,Da Xiao,Tianhui Li,Zhiliang Ku,Jiang He,Xinxin Yu,Yong Peng

doi:10.1038/s41598-017-18970-y

Abstract

Large-area, pinhole-free CH3NH3PbI3 perovskite thin films were successfully fabricated on 5 cm × 5 cm flexible indium tin oxide coated polyethylene naphthalate (ITO-PEN) substrates through a sequential evaporation/spin-coating deposition method in this research. The influence of the rate-controlled evaporation of PbI2 films on the quality of the perovskite layer and the final performance of the planar-structured perovskite solar cells were investigated. An ultrafast evaporation rate of 20 Å s−1 was found to be most beneficial for the conversion of PbI2 to CH3NH3PbI3 perovskite. Based on this high-quality CH3NH3PbI3 film, a resultant flexible perovskite solar sub-module (active area of 16 cm2) with a power conversion efficiency of more than 8% and a 1.2 cm2 flexible perovskite solar cell with a power conversion efficiency of 12.7% were obtained.

Highlights

Large-area, pinhole-free CH3NH3PbI3 perovskite thin films were successfully fabricated on 5 cm × 5 cm flexible indium tin oxide coated polyethylene naphthalate (ITO-PEN) substrates through a sequential evaporation/spin-coating deposition method in this research
Fullerene C60 was selected as an electron transport material (ETL) and first evaporated onto a indium tin oxide-coated polyethylene naphthalate (ITO-PEN) flexible substrate[17]
PbI2 was evaporated on this amorphous C60 layer at various controlled deposition rates within the range of 0.5 Å s−1 to 40 Å s−1, which could be adjusted by controlling the evaporation source temperature

Summary

Introduction

Large-area, pinhole-free CH3NH3PbI3 perovskite thin films were successfully fabricated on 5 cm × 5 cm flexible indium tin oxide coated polyethylene naphthalate (ITO-PEN) substrates through a sequential evaporation/spin-coating deposition method in this research. In all steps of F-PSC module/ sub-module fabrication, preparing pinhole-free, uniform perovskite films with large areas and high reproducibility is the most important challenge This is because either the widely used metal halide predecessor PbI2 or the resultant perovskite materials, such as CH3NH3PbI3 (MAPbI3), demonstrate specific solution crystallization processes in which the nucleation rates do not match the crystallization rates[11]. Combining the merits of the low cost, short processing time, full coverage of the substrate, and high module performance, the PbI2 film fabricated via ultrafast thermal evaporation holds promise for facilitating the development of industrial-scale perovskite solar cells

Methods

Results

Conclusion