The effect of n-Butanol on regulating the solubility-temperature characteristics for the Growth of High-Quality CsPbBr3 Single Crystals

Abstract

The growth of all-inorganic CsPbBr3 single crystals requires a temperature below 88 °C in order to avoid the orthorhombic to tetragonal phase transition. Here, we report a low-temperature inverse temperature crystallization strategy based on a DMSO/n-butanol (NBA) mixed solvent system. Unlike the other alcohols, monotonic retrograde solubility behavior of CsPbBr3 in the temperature range of 20-80 °C is achieved only when NBA is adopted, which enables crystal growth at a reduced temperature with a high yield of up to 44.4%. The resulting CsPbBr3 crystals show high phase purity without CsPb2Br5, a narrow XRC FWHM down to 0.035°, high optical transmittance (75.4%), and prolonged carrier lifetimes (τ2= 55.4 ns, τavg ≈ 50.2 ns). Schottky-type detectors exhibit a low dark current of 8 nA at 100 V and a hole μτ of 0.67 × 10-4 cm2 V-1, demonstrating the promise of this solvent-engineering route for radiation detection applications.