Near room temperature synthesis of Cs2InCl5-xBrx·H2O (x = 0–5) perovskites with tunable yellow to red emissions

Lead-free halide perovskites have recently evoked considerable interest in illumination and display, due to their intriguing optical properties. Herein, we present an efficient and facile strategy to prepare Cs2InCl5-xBrx·H2O (x = 0–5) perovskites. The preparation was performed at a low temperature of 80 °C under atmospheric pressure, and required no complex technological process. Comparing with that prepared by the traditional hydrothermal method, the emission intensity of the prepared Cs2InX5·H2O (X = Cl/Br) perovskites were increased by two times. Besides, Sb3+ ions were successfully doped into the matrix of Cs2InX5·H2O (X = Cl/Br) by our method. After doping with Sb3+, the emission intensities of Cs2InX5·H2O were greatly enhanced, with enhanced by a factor of ∼187 and ∼102, respectively. Importantly, the PLQYs were greatly improved, reaching 79.6% and 42.7%, respectively. Additionally, the effects of Br− on luminescent properties of Cs2InCl5-xBrx·H2O:Sb3+ (x = 0–5) were also investigated in this work. Though the control of the Br− content, tunable emissions from 575 nm to 630 nm were achieved. These results indicate the prepared samples could be promising environmentally-friendly materials for lightings. Furthermore, this work presents a reliable and simple method for preparing high-quality perovskites.