School of Materials Science and Engineering, Beihang University, Beijing, 100191, China.
Yunnan Key Laboratory for Micro/Nano Materials and Technology, School of Materials and Energy, Yunnan University, Kunming, 650091, China.
Adv Mater. 2023 May;35(21):e2212160. doi: 10.1002/adma.202212160. Epub 2023 Mar 30.
Cesium-formamidinium lead iodide perovskite quantum dots (FA Cs PbI PQDs) show high potential for next-generation photovoltaics due to their outstanding optoelectronic properties. However, achieving composition-tunable hybrid PQDs with desirable charge transport remains a significant challenge. Herein, by leveraging an antisolvent-assisted in situ cation exchange of PQDs, homogeneous FA Cs PbI PQDs with controllable stoichiometries and surface ligand chemistry are realized. Meanwhile, the crystallographic stability of PQDs is substantially improved by substituting the cations of the PQDs mediated by surface vacancies. Consequently, PQD solar cell delivers an efficiency of 17.29%, the highest value among the homostructured PQD solar cells. The high photovoltaic performance is attributed to the broadened light harvesting spectra, flattened energy landscape, and rationalized energy levels of highly oriented PQD solids, leading to efficient charge carrier extraction. This work provides a feasible approach for the stoichiometry regulation of PQDs to finely tailor the optoelectronic properties and tolerance factors of PQDs toward high-performing photovoltaics.
铯甲脒碘化铅钙钛矿量子点（FA Cs PbI PQDs）具有优异的光电性能，有望成为下一代光伏材料。然而，实现具有理想电荷输运性能的可调控混合 PQDs 仍然是一个重大挑战。在此，通过利用反溶剂辅助原位 PQDs 阳离子交换，实现了具有可控化学计量比和表面配体化学的均匀 FA Cs PbI PQDs。同时，通过表面空位介导的 PQDs 阳离子取代，显著提高了 PQDs 的晶体稳定性。因此，PQD 太阳能电池的效率达到了 17.29%，在同构 PQD 太阳能电池中达到了最高值。这种高光伏性能归因于拓宽的光捕获光谱、平坦的能量势垒和高度有序 PQD 固体的合理能级，从而实现了高效的电荷载流子提取。这项工作为 PQDs 的化学计量比调控提供了一种可行的方法，以精细调整 PQDs 的光电性能和容限因子，从而实现高性能光伏。
