@article{oai:oist.repo.nii.ac.jp:00002311,
 author = {Tong, Guoqing and Son, Dae-Yong and Ono, Luis K. and Kang, Hyung-Been and He, Sisi and Qiu, Longbin and Zhang, Hui and Liu, Yuqiang and Hieulle, Jeremy and Qi, Yabing},
 journal = {Nano Energy},
 month = {May},
 note = {Defects as a result of structural imperfections and/or extrinsic impurities in the perovskite films have a detrimental effect on efficiency and stability of perovskite solar cells (PSCs). Here, we propose to use pre-synthesized crystalline perovskite with perfect stoichiometry to control and lower the density of defects from precursors by the powder engineering method. Compared with raw materials (i.e., PbI₂ and FAI) based perovskites, the average efficiency of the PSCs fabricated based on these pre-synthesized perovskite precursors increased from 18.62% to 19.85%. Moreover, the unwanted intermediate chemical compositions (i.e., the unreacted phases and residual solvent) in the raw material-based perovskite films were significantly reduced in the pre-synthesized δ-FAPbI₃ and α-FAPbI₃ perovskites according to the secondary ion mass spectroscopy depth profiling results. Finally, we obtained the champion efficiency of 22.76% for α-FAPbI₃ and 23.05% for FAPb(I0.9Br0.1)₃ based PSCs. Long-term operational stability measurements of the encapsulated FAPb(I₀.₉Br₀.₁)3 based PSCs showed a slow decay and maintained the efficiency about 88% after 1200 h (T₈₀ > 2000 h). Furthermore, a proof-of-concept integrated perovskite solar module-lithium ion battery-light-emitting diode device was demonstrated.},
 title = {Removal of residual compositions by powder engineering for high efficiency formamidinium-based perovskite solar cells with operation lifetime over 2000 hours},
 volume = {87},
 year = {2021}
}