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 other alcohols, the 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 and τ_avg ≈ 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.