Surface ligand engineering of CsPbBr3 perovskite nanowires for high-performance photodetectors

Surface ligand engineering is of great importance for the preparation of one-dimensional (1D) CsPbBr 3 nanowires for high-performance photodetectors. The traditional long-chain terminated ligands such as oleylamine/oleic acid (C18) used in the preparation of CsPbBr 3 nanowires will form an electrically insulating layer on the surface of the nanowires, which hinders the effective transport of charge carriers in optoelectronic devices. In this paper, short-chain ligands, including dodecylamine/dodecanoic acid (C12), octylamine/octanoic acid (C8) and hexylamine/hexanoic acid (C6), are introduced to partially replace long-chain ligands (C18) to successfully prepare various CsPbBr 3 nanowires via a solvothermal method. Microstructure characterization indicates that the four kinds of nanowires before/after surface ligand engineering, which are named as C18-CsPbBr 3 , C12/18-CsPbBr 3 , C8/18-CsPbBr 3 and C6/18-CsPbBr 3 , all have high aspect ratio and purity. As compared with CsPbBr 3 with long-chain terminated ligands, the C8/18-CsPbBr 3 and C6/18-CsPbBr 3 nanowires with shorter chain ligands exhibit superior photoluminescence (PL) performance and stability under adverse conditions such as ultraviolet irradiation and high temperature. The constructed photodetectors based on C8/18-CsPbBr 3 and C6/18-CsPbBr 3 nanowires have shown improved performances. This work provides a new idea for the preparation of CsPbBr 3 nanowires with high optical properties, stability and charge transport, and the prepared CsPbBr 3 nanowires have potential application prospects in optoelectronic devices.