Efficient blue CsPbBr3 perovskite nanocrystals synthesis with the assistance of zwitterionic straight chain amino acids

Abstract

Metal-halide perovskite nanocrystals (NCs) are promising semiconductor materials for the application of novel nano-optoelectronic devices and light sources, which have attracted wide attention in recent years. Many additives were applied for modulating the electronic structure, as well as improving the stability or light efficiency of the perovskite NCs, particularly the zwitterionic molecules show strong and unique interaction with perovskite lattice to passivate the defects and surface state of the perovskite NCs. Here, in this work, we synthesized the blue CsPbBr3 perovskite NCs with the assist of zwitterionic straight-chain amino acids, and systematically studied the interaction between the perovskite and amino acids with varied molecular structure. We found that the polarization of the amino acid molecules dominates the ionized state of the two functional groups of -NH2 and -COOH, leading to different interaction with perovskite. Eventually, the perovskite NCs with 7-aminophenic acid show stable and efficient blue light emission at peak wavelength of 475 nm with achieved light efficiency of ∼ 90%. This work demonstrated the mechanism of the interaction between series zwitterionic amino acids and perovskite experimentally, which provides a guideline for the additive selection and design.