Controllable metastable growth of perovskite single crystals for highly sensitive X-ray detection

Abstract

Single crystalline perovskites with long carrier lifetime, large carrier mobility and high atomic number emerge as highly sensitive X-ray detection materials. Precisely controlling the growth of high-quality perovskite single crystals (SCs) is still a big challenge to date. Herein, a simple, convenient and highly reproducible method, low-temperature controllable metastable crystallization (LCMC), is shown to prepare high-quality CH₃NH₃PbBr₃ (MAPbBr₃) SCs at a low temperature of 45 °C. A surprisingly reduced full width at half-maximum of the (001) and (002) planes and hence a higher crystalline quality was achieved for the LCMC-MAPbBr₃ SCs as compared to the inverse temperature crystallization (ITC) SCs. Moreover, the LCMC-MAPbBr₃ SCs possess longer carrier lifetime increased by nearly 248% to 1126 ns, larger carrier mobility increased by 146% to 87.8 cm² V⁻¹ s⁻¹, and significantly lower trap density of 2.1 × 10⁹ cm⁻³ (reduced by around 89%) compared with the ITC samples. Based on the high-quality SCs, the as-developed X-ray detector demonstrates a high sensitivity of 2975.7 μC Gy_air⁻¹ cm⁻² and a lowest detectable dose rate of 0.48 μGy_air s⁻¹. Evidently, this work may pave the way for controlling the crystallization process of perovskites, which is essential for enhancing the further application of perovskite SCs.