Yu Qi, Sun Wentian, Tang Shu
Huailai Shengshi New Energy Technology Co., Ltd., Zhangjiakou 075400, China.
School of Science, China University of Geosciences Beijing, Beijing 100083, China.
Nanomaterials (Basel). 2024 Oct 14;14(20):1651. doi: 10.3390/nano14201651.
CsPbIBr, with its suitable bandgap, shows great potential as the top cell in tandem solar cells. Nonetheless, its further development is hindered by a high defect density, severe carrier recombination, and poor stability. In this study, CsPbIBr quantum dots were utilized as an additive in the ethyl acetate anti-solvent, while a layer of CsPbBr QDs was introduced between the ETL and the CsPbIBr light-harvester film. The combined effect of these two QDs enhanced the nucleation, crystallization, and growth of CsPbIBr perovskite, yielding high-quality films characterized by an enlarged crystal size, reduced grain boundaries, and smooth surfaces. And a wider absorption range and better energy band alignment were achieved owing to the nano-size effect of QDs. These improvements led to a decreased defect density and the suppression of non-radiative recombination. Additionally, the presence of long-chain organic molecules in the QD solution promoted the formation of a hydrophobic surface, significantly enhancing the long-term stability of CsPbIBr PSCs. Consequently, the devices achieved a PCE of 9.20% and maintained an initial efficiency of 85% after 60 days of storage in air. Thus, this strategy proves to be an effective approach for the preparation of efficient and stable CsPbIBr PSCs.
具有合适带隙的CsPbIBr作为串联太阳能电池的顶电池显示出巨大潜力。然而，其进一步发展受到高缺陷密度、严重的载流子复合和较差稳定性的阻碍。在本研究中，CsPbIBr量子点被用作乙酸乙酯反溶剂中的添加剂，同时在电子传输层（ETL）和CsPbIBr光收集膜之间引入一层CsPbBr量子点。这两种量子点的联合作用增强了CsPbIBr钙钛矿的成核、结晶和生长，得到了高质量的薄膜，其特征在于晶体尺寸增大、晶界减少和表面光滑。并且由于量子点的纳米尺寸效应，实现了更宽的吸收范围和更好的能带排列。这些改进导致缺陷密度降低和非辐射复合受到抑制。此外，量子点溶液中长链有机分子的存在促进了疏水表面的形成，显著提高了CsPbIBr钙钛矿太阳能电池的长期稳定性。因此，这些器件实现了9.20%的功率转换效率（PCE），并且在空气中储存60天后保持了85%的初始效率。因此，该策略被证明是制备高效稳定的CsPbIBr钙钛矿太阳能电池的有效方法。
