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Thermal-Induced Volmer–Weber Growth Behavior for Planar Heterojunction Perovskites Solar Cells
journal contribution
posted on 2015-07-28, 00:00 authored by Yi Chu Zheng, Shuang Yang, Xiao Chen, Ying Chen, Yu Hou, Hua Gui YangRecently, a hot casting technique
was developed to prepare pinhole
free perovskite thin films with millimeter-scale grains. However,
its intrinsic formation mechanism has not been studied in the literature
up to now. Here, we demonstrate a Volmer–Weber growth mechanism
during the hot casting, a process that typically involves the formation
of island shaped grains and the following integration into dense perovskite
films. It was found that such crystal growth was determined by the
multiple effect of thermal energy and force centrifugal field. Particularly,
the thermal energy can facilitate the formation of CH3NH3PbI3 and overcome the energy barriers of the precursor
solutions on the substrates. The detailed morphologies of CH3NH3PbI3 films can be optimized by regulating
deposition parameters including casting temperature and rotate speed.
Solar cells constructed with these thin films achieve an average power
conversion efficiency of 12.6 ± 0.3% under standard AM 1.5 G
conditions.