Angew. Chem. Int. Ed.: In-situ Ligand Bonding Management of CsPbI3 Perovskite Quantum Dots Enables High-Performance Photovoltaics and Red Light-Emitting Diodes

Title：

In-situ ligand bonding management of CsPbI₃ perovskite quantum dots enables high-performance photovoltaics and red light-emitting diodes

Authors：

Junwei Shi¹, Fangchao Li¹, Yan Jin¹, Cheng Liu¹, Ben Cohen-Kleinstein², Shuai Yuan¹, Youyong Li¹,   Zhao-Kui Wang¹, Jianyu Yuan¹,* Wanli Ma¹*

Institutions：

¹Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, 199 Ren-Ai Road, Suzhou Industrial Park, Suzhou, Jiangsu 215123, P. R. China

²Waterloo Institute of Nanotechnology Engineering, University of Waterloo, Waterloo, ON, Canada N2L 3G1

Abstract：

Lead halide perovskite quantum dots (QDs) are promising materials for the next generation optoelectronic devices. Importantly, the bonding nature of QD capping ligands plays a crucial role in the resultant device performance. To fine-tuning the surface ligand towards high-performance devices, we first developed an in-situ passivation process for all-inorganic cesium lead iodide (CsPbI₃) perovskite QDs by using a bi-functional ligand, namely L-phenylalanine (L-PHE). Through the addition of this ligand into the precursor solution during synthesis, the in-situ treated CsPbI₃ QDs display significantly reduced surface states, increased vacancy formation energy, higher photoluminescence quantum yields, and much improved stability. Consequently, the L-PHE passivated CsPbI₃ QDs enabled us to realize QD solar cells with an optimal efficiency of 14.62% and red light-emitting diodes (LEDs) with a highest external quantum efficiency (EQE) of 10.21%, respectively, demonstrating the great potential of ligand bonding management in improving the optoelectronic properties of solution-processed perovskite QDs.

IF：

12.257

Link：

https://doi.org/10.1002/anie.202010440