聚乙二醇掺杂对铋基钙钛矿薄膜形貌和性能影响

Effects of PEG doping on morphology and properties of bismuth- based perovskite films

钙钛矿太阳能电池的光电转换效率已由3.8%迅速攀升到25.02%。然而,铅基钙钛矿的毒性和不稳定性严重限制了其商业化应用。在空气中稳定且低毒性的铋基钙钛矿材料((CH3NH3)3Bi2I9,MBI)吸引了研究者们的广泛关注。MBI以六边形晶体无序地堆积形成铋基钙钛矿薄膜,这种无序的堆积导致MBI薄膜致密性低,且存在大量针孔缺陷,严重影响了基于MBI薄膜的太阳能电池的整体性能。本文研究了聚乙二醇(PEG)掺杂到MBI前驱体溶液中对MBI薄膜微观形貌的影响,并系统地研究了聚乙二醇的掺杂浓度对基于MBI薄膜的太阳能电池的光电性能的影响。结果表明,当PEG的浓度为30 mg/mL时,成功地制得了均匀致密的MBI薄膜,基于该薄膜的电池器件的最佳光电转换效率为0.14%.

The photoelectric conversion efficiency of perovskite solar cells(PSCs)has rapidly increased from 3.8% to 25.02%.However,the toxicity and instability of lead-based perovskite have seriously limited its commercial application.The air-stable and low-toxic bismuth-based perovskite((CH3NH3)3Bi2I9,MBI)has attracted widely attention of researchers.MBI formed bismuth-based perovskite films by disordered stacking of hexagonal crystals,resulting in low density of the MBI film and a large number of pinhole defects,which dramatically affected the performance of MBI-based PSCs.In this paper,the effect of polyethylene glycol doped(PEG)into MBI precursor solution on the MBI thin film morphology was studied,and the effect of PEG doping concentration on the photoelectrical properties of MBI film based solar cell was also systematically investigated.It revealed that when the PEG doping concentration was 30 mg/mL,a uniform and dense MBI film was obtained,and the best efficiency of the device based on this film was 0.14%.