Abstract：
The smooth and dense light-absorbing layer is an essential factor in polycrystalline solar cells to achieve high photovoltaic performance, while it remains challenging in perovskite solar cells because of the difficulty balancing the speed of crystal nucleation and growth in a solution way. Here, we explored a perovskite nucleation/growth compatible model via manipulating the intermediate complex induced by n-hexylamine (NHA) molecule, guiding us to adjustments perovskite nucleation and growth process. We found that the NHA can act as a gearbox-like molecule to sequentially reduce the perovskite nucleation barrier, promote the nucleation velocity, and retard the perovskite growth simultaneously to obtain uniform perovskite films; correspondingly, this modulation also yields the buried interface with fewer voids and low defects density. In addition, the hydrophobic NHA with long alkyl chain improves the moisture tolerance of the perovskite. The treated solar cell power conversion efficiency was 21.91 %. Importantly, in ∼ 70 % humidity at 25 °C for 30 days, the efficiency of the device declined less than 5 %, exhibiting a good stability performance.
摘要：
光滑致密的光吸收层是多晶太阳能电池实现高光伏性能的重要因素,虽然在钙钛矿太阳能电池中仍然具有挑战性，因为难以平衡晶体成核和生长的速度。这里,我们通过操纵正己胺（NHA）分子诱导的中间复合物，探索了钙钛矿成核/生长相容模型，指导我们调整钙钛矿成核和生长过程。我们发现NHA可以充当类似变速箱的分子，以依次降低钙钛矿成核屏障，促进成核速度，同时延缓钙钛矿生长，获得均匀的钙钛矿薄膜；相应地，这种调制还产生具有较少空隙和低缺陷密度的掩埋界面。此外,具有长烷基链的疏水性NHA提高了钙钛矿的耐湿性。经处理的太阳能电池功率转换效率为21.91%。重要的是,在25°C的70%湿度下持续30天，设备的效率下降不到5%，表现出良好的稳定性能。
