NMP溶剂退火制备高效钙钛矿太阳电池

Efficient perovskite solar cells fabricated through NMP solvent annealing

钙钛矿薄膜中的PbI2缺陷会引起载流子复合,降低电池性能。通过对一步法制备的钙钛矿薄膜进行NMP(N-甲基吡咯烷酮)溶剂退火,减少热处理过程中有机阳离子的损失,实现钙钛矿晶界处PbI2缺陷的减少,同时增大晶粒尺寸、实现薄膜粗糙度及起伏度的调控。结果表明NMP溶剂退火方法可抑制薄膜中的非辐射复合,降低缺陷态浓度,实现薄膜光吸收的增强,从而提高钙钛矿太阳电池的短路电流和填充因子。与未经过NMP溶剂退火处理的电池相比,该方法制备的钙钛矿太阳电池的平均效率提高10.51%,最高效率提高22.15%。

PbI2defects in the perovskite films may cause carrier recombination,resulting in the degradation of device performances.The fabricated perovskite films through one-step spin-coating method was treated by solvent annealing with NMP(N-Methyl-2-pyrrolidinone),which reduces the loss of organic cation during the thermal annealing process,thus leading to the decrease of PbI2defects located in the grain boundaries.Meanwhile,larger grain sizes and the control of the roughness,waviness of the films are realized.The result shows that the NMP solvent annealing inhibits the nonradiative recombination in the perovskite films and decreases the concentrations of the trap states,while increasing the light absorption of the films.So,the short circuit current and fill factor of the perovskite solar cells are enhanced.Compared with devices without NMP solvent annealing treatment,the average and the optimal efficiency of the as-prepared perovskite solar cells based on this method increase by10.51%and22.15%,respectively.