Zhang Xuliang, Qian Yuli, Ling Xufeng, Wang Yao, Zhang Yannan, Shi Junwei, Shi Yao, Yuan Jianyu, Ma Wanli
Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Soochow University, 199 Ren-Ai Road, Suzhou Industrial Park, Suzhou 215123, Jiangsu, P. R. China.
ACS Appl Mater Interfaces. 2020 Jun 17;12(24):27307-27315. doi: 10.1021/acsami.0c07667. Epub 2020 Jun 8.
As effective light absorbers in solar cells, CsPbI all-inorganic perovskite quantum dots (QDs) have received increasing attention, benefitting from their suitable optical band gap and thermal stability. However, the easy cubic to yellow orthorhombic phase transition hinders their further application in stable photovoltaic devices. CsPbBr QDs have been targeted as a promising material for ultrahigh voltage and stable solar cells. In this work, we first develop a simple yet efficient post-treatment method using guanidinium thiocyanate (GASCN), which is able to exchange the native capping ligands of CsPbBr QDs, thus improving the carrier transport properties through enhanced electrical coupling between QDs. Additionally, the morphology and crystalline properties of solid QD films are also improved. Therefore, simultaneously improved open-circuit voltage (), short-circuit current density (), and fill factor (FF) were obtained in the corresponding CsPbBr QD devices. Finally, the QD solar cells based on optimal hole-transporting layers delivered the highest efficiency exceeding 5% together with an ultrahigh of 1.65 V, representing the most efficient CsPbBr QD solar cells to date. More importantly, the CsPbBr perovskite QD solar cells developed here exhibit excellent stability, ultrahigh voltage, and high transparency over the entire visible spectrum region, demonstrating their great potential in applications like solar windows of greenhouse and hydrogen generation driven by perovskite solar cells.
作为太阳能电池中的有效光吸收剂，CsPbI全无机钙钛矿量子点（QDs）因其合适的光学带隙和热稳定性而受到越来越多的关注。然而，从立方相到黄色正交相的容易转变阻碍了它们在稳定光伏器件中的进一步应用。CsPbBr量子点已被视为超高压和稳定太阳能电池的一种有前途的材料。在这项工作中，我们首先开发了一种简单而有效的后处理方法，使用硫氰酸胍（GASCN），它能够交换CsPbBr量子点的天然封端配体，从而通过增强量子点之间的电耦合来改善载流子传输特性。此外，固体量子点薄膜的形态和结晶性能也得到了改善。因此，在相应的CsPbBr量子点器件中同时提高了开路电压（）、短路电流密度（）和填充因子（FF）。最后，基于最佳空穴传输层的量子点太阳能电池实现了超过5%的最高效率以及1.65 V的超高，代表了迄今为止最有效的CsPbBr量子点太阳能电池。更重要的是，这里开发的CsPbBr钙钛矿量子点太阳能电池在整个可见光谱区域表现出优异的稳定性、超高压和高透明度，证明了它们在温室太阳能窗和钙钛矿太阳能电池驱动的制氢等应用中的巨大潜力。
