Surface integration modulated low-temperature synthesis for high-quality halide perovskite single crystals

Advancements in optoelectronic devices are largely contingent on the availability of superior-quality semiconductor materials, such as halide perovskites. However, quickly producing halide perovskite single crystals (SCs) often leads to compromised material properties hindering high-end applications. To address this challenge, we developed a refined crystal growth methodology, low-temperature inverse temperature crystallization (LITC), tailored to enhance the quality of perovskite SCs while maintaining a relatively fast growth rate. Taking the synthesis of MAPbBr₃ SCs as a model, isopropyl alcohol (IPA) was introduced into the precursors as an additive. The affinity of IPA for the crystal surface enables a modulated surface integration process and simultaneously impacts the charge of colloids within the precursor solutions to suppress undesirable nucleation. Thereafter, MAPbBr₃ SCs can successfully grow under near-equilibrium conditions from 44 °C to 48 °C. Notably, a narrow full width at half maximum of 0.012° in the rocking curve of high-resolution X-ray diffraction was achieved, outperforming most inverse temperature crystallization (ITC) methods for SC synthesis. X-ray detectors fabricated with LITC SCs exhibited markedly improved performances. With meticulous surface integration control, this work advances the synthesis of high-quality perovskite SCs and paves the way for elevating the performance and durability of optoelectronic devices.