Lead-free cesium tin halide nanocrystals for light-emitting diodes and color down conversion

• Published in: RSC advances Vol. 1; no. 61; pp. 37161 - 37167
• Main Authors: Mahesh, K. P. O, Chang, Che-Yu, Hong, Wei-Li, Wen, Tzu-Hsiang, Lo, Pei-Hsuan, Chiu, Hao-Zhe, Hsu, Ching-Ling, Horng, Sheng-Fu, Chao, Yu-Chiang
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 07.10.2020; The Royal Society of Chemistry
• Subjects: Cesium; Chemistry; Color; Conversion; Current carriers; Excitons; Lead content; Lead free; Light emitting diodes; Nanocrystals; Optical properties; Perovskites; Photoluminescence; Physical properties; Spectrum analysis; Synthesis; Temperature dependence; Toxicity
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d0ra06139e

Organometal halide perovskites are attracting a great deal of attention because of their long carrier diffusion lengths, wide wavelength tunability, and narrow-band emission. However, the toxicity of lead has caused considerable environmental and health concerns. In this work, lead-free cesium tin halide nanocrystals are synthesized and investigated. CsSnBr 3 and CsSnI 3 nanocrystals, 25 and 7 nm in size, are synthesized by a facile hot injection method. Absorption spectroscopy, photoluminescence spectroscopy, and X-ray diffraction were used to understand their structural and optical properties. CsSnBr 3 and CsSnI 3 nanocrystals show emission peaks at 683 and 938 nm, respectively. These nanocrystals show shelf stability for a few months. Temperature-dependent photoluminescence is utilized to know more about fundamental physical parameters, such as exciton binding energy, charge carrier-phonon interactions and band gap. Light-emitting diodes and color down-conversion films are also demonstrated using these lead free perovskite nanocrystals. Organometal halide perovskites are attracting a great deal of attention because of their long carrier diffusion lengths, wide wavelength tunability, and narrow-band emission.