In Situ Ligand Bonding Management of CsPbI3 Perovskite Quantum Dots Enables High‐Performance Photovoltaics and Red Light‐Emitting Diodes

• DOI: 10.1002/ange.202010440
• Publication Date: 2020-08-25T06:49:41Z
• Authors: Junwei Shi; Fangchao Li; Yan Jin; Cheng Liu; Ben Cohen‐Kleinstein; Shuai Yuan; Youyong Li; Zhao‐Kui Wang; Jianyu Yuan; Wanli Ma
• Keywords: Passivation; Quantum Efficiency

Abstract To fine‐tune surface ligands towards high‐performance devices, we developed an in situ passivation process for all‐inorganic cesium lead iodide (CsPbI 3 ) perovskite quantum dots (QDs) by using a bifunctional ligand, L‐phenylalanine (L‐PHE). Through the addition of this ligand into precursor solution during synthesis, treated CsPbI QDs display significantly reduced states, increased vacancy formation energy, higher photoluminescence yields, and much improved stability. Consequently, L‐PHE passivated enabled realization QD solar cells with optimal efficiency 14.62 % red light‐emitting diodes (LEDs) highest external (EQE) 10.21 %, respectively, demonstrating great potential bonding management improving optoelectronic properties solution‐processed QDs.