In Situ Low-Temperature Growth and Superior Luminescent Property of Well-Aligned, High-Quality Cubic CsPbBr 3 Micrometer-Scale Single Crystal Arrays on Transparent Conductive Substrates.

Direct assembly of high-quality single-crystal perovskite microarrays on transparent conductive substrates and carrier injection layers is vital to realize high-performance optoelectronic devices. Although cubic-phase CsPbBr 3 is considered to have a higher structural and optical quality than the orthorhombic one, obtaining a well-aligned assembly directly on the aforementioned substrates is still challenging. Here we developed a solvent-assisted crystallization strategy with the assistance of surface modifiers, through which the in situ low-temperature growth of well-aligned cubic single-crystal CsPbBr 3 microarray with a preferential out-of-plane [100] orientation is achieved for the first time on commercial transparent conductive substrates. As compared with the control orthorhombic samples, the cubic CsPbBr 3 single crystals possess superior properties including a higher photoluminescence internal quantum efficiency, fewer defect states, a weaker scattering by phonons, and an appearance of lasing. The results presented here can pave the way for future design and applications of optoelectronic devices based on perovskite microarrays.