Special Display and Imaging Technology Innovation Center of Anhui Province, Anhui Province Key Laboratory of Measuring Theory and Precision Instrument, Anhui Province Key Laboratory of Advance Functional Materials and Devices, Academy of Opto-Electric Technology, Hefei University of Technology, Hefei 230009, China.
Instrumental Analysis Center, Hefei University of Technology, Hefei 230009, China.
Nanoscale. 2023 Jun 8;15(22):9691-9699. doi: 10.1039/d3nr00602f.
Methyl acetate (MeOAc) is the most used antisolvent in the preparation of perovskite quantum dot (QD) films. However, the hydrolysis of MeOAc results in acetic acid and methanol (MeOH), and the decomposition of the perovskite occurs more easily under acidic and polar conditions. Herein, we report a facile and universal anion modification strategy to inhibit MeOH absorption on a perovskite QD surface and improve the photovoltaic performance of perovskite QD solar cells, which is implemented by incorporating a series of guanidinium salts containing different anions (guanidinium bromide (GuaBr), guanidinium thiocyanate (GuaSCN), and guanidinium acetate (GuaAc)). All anions play a positive role in inhibiting the absorption of MeOH on the QD surface, facilitating charge transfer between perovskite QDs and passivating the defects. Moreover, the regulation of surface chemistry can be optimized by rational tailoring of different anion species. The GuaAc-based devices deliver a PCE of 7.04%, which is the highest value among inorganic CsPbBr QD solar cells. More importantly, the CsPbBr QD solar cells exhibit high transparency over the entire visible spectrum region, indicating their promising application in solar windows.
醋酸甲酯（MeOAc）是制备钙钛矿量子点（QD）薄膜最常用的抗溶剂。然而，MeOAc 的水解会产生乙酸和甲醇（MeOH），而且在酸性和极性条件下，钙钛矿更容易分解。在此，我们报道了一种简便通用的阴离子修饰策略，通过引入一系列含有不同阴离子的胍盐（溴化胍（GuaBr）、硫氰酸胍（GuaSCN）和醋酸胍（GuaAc））来抑制钙钛矿 QD 表面对 MeOH 的吸收，从而提高钙钛矿 QD 太阳能电池的光伏性能。所有阴离子都对抑制 QD 表面 MeOH 的吸收起到了积极作用，促进了钙钛矿 QD 之间的电荷转移，并钝化了缺陷。此外，通过合理调整不同阴离子种类，可以优化表面化学的调节。基于 GuaAc 的器件的光电转换效率（PCE）达到了 7.04%，这是无机 CsPbBr QD 太阳能电池中的最高值。更重要的是，CsPbBr QD 太阳能电池在整个可见光光谱区域具有高透明度，表明它们在太阳能窗中的应用具有很大的潜力。
