Researchers report an optofluidic crystallithography method for directed growth of single-crystalline halide perovskites
Crystallization, the phenomenon that transforms disordered atoms or molecules into ordered solid-state structures, is an immensely studied process. However, while researchers have made significant strides in controlling the nucleation of crystals from precursor solutions, directing their subsequent growth to form defect-free single crystals with tailored shapes has proven far more challenging. This limitation has been particularly problematic for materials like halide perovskites, where controlling the formation of defects results in better photoelectric properties. Conventional techniques like inverse temperature crystallization or antisolvent vapor-assisted crystallization allow some control over average growth conditions, but their ability to pattern arbitrary single-crystal geometries while suppressing defect formation has remained confined.
Now, researchers at Tsinghua University have demonstrated optofluidic crystallithography (OCL), a novel approach that leverages a laser as a precise "pen" to simultaneously control the shape and quality of single-crystal halide perovskites as they grow from solution at record speeds.