Morphology-controlled CH3NH3PbI3 films by hexane-assisted one-step solution deposition for hybrid perovskite mesoscopic solar cells with high reproductivity

作者：Lin Na; Qiao Juan^*; Dong Haopeng; Ma Fusheng; Wang Liduo

来源：Journal of Materials Chemistry A, 2015, 3(45): 22839-22845.

DOI：10.1039/c5ta04051e

The morphology and crystal structure of perovskite films are critical for achieving high-performance perovskite solar cells; however in most cases, the conventional one-step solution deposition method hardly yields a homogeneous perovskite film over a large area, especially for CH3NH3PbI3. Here, we propose a facile and environmentally friendly hexane-assisted one-step solution approach for dense and uniform CH3NH3PbI3 thin films. According to the phase diagram of immiscible liquids, n-hexane was chosen as the assistant solvent to speed-up the evaporation of the main solvent N,N-dimethylformamide (DMF) during the solution deposition process, thus significantly promoting the nucleation and crystallization process of CH3NH3PbI3 perovskite. The as-prepared CH3NH3PbI3 films demonstrated a uniform and dense morphology, and enhanced light absorption in a long-wavelength range. In particular, such n-hexane treatment could help eliminate the residual DMF and greatly improve the thermal stability of the obtained perovskite films. The full solution-processed CH3NH3PbI3 solar cells using n-hexane treatment exhibited a maximum power conversion efficiency of 11.7% and average efficiencies of 11.3 +/- 0.4% under standard AM 1.5 conditions in comparison with 7.0 +/- 0.4% of the conventional cells. The recombination resistance of the cells increased nearly 5 times by using n-hexane. These results suggest that this hexane-assisted one-step solution approach is promising for controlling the crystallization process of perovskites to achieve high-performance perovskite solar cells.

• 出版日期2015
• 单位清华大学