|Title||Phase-Control of Single-Crystalline Inorganic Halide Perovskites via Molecular Coordination Engineering|
|Publication Type||Journal Article|
|Year of Publication||2022|
|Authors||Lin, Q, Bernardi, S, Shabbir, B, Ou, Q, Wang, M, Yin, W, Liu, S, Chesman, ASR, Fürer, SO, Si, G, Medhekar, N, ,, Widmer-Cooper, A, Mao, W, Bach, U|
The excellent optoelectronic properties and structural stability of inorganic cesium lead halide perovskites make them promising candidates for multiple types of optoelectronic devices. However, it remains a challenge to fabricate monocrystalline phase-pure perovskite microstructures by facile low-temperature solution-based methods. Herein, a solution-based method is demonstrated for controlling the crystallization of cesium halide perovskite microstructures. The structure of perovskite crystals is successfully tuned from non-corner sharing Cs4PbBr6 (0D) to corner-sharing CsPbBr3 (3D) to layered CsPb2Br5 (2D) by controlling water (H2O) to dimethylsulfoxide (DMSO) ratios. Molecular dynamics simulations and thermodynamic analysis indicate that the relative stability of Pb2+ and Br− ions in solution is the key factor in determining which crystals form at different H2O/DMSO ratios, with Cs+ simply incorporated as needed. The phase-pure 0D crystals exhibit a high photoluminescence quantum yield of 41%, whilst the 2D crystals have an onset of absorption at 350 nm. Furthermore, the as-synthesized, highly uniform 3D perovskite single crystals are coupled with nanofabricated interdigitated electrodes to show excellent X-ray detection, with a high sensitivity of 8000 μC Gyair−1cm−2 obtained under a 0.5V external bias. This is comparable to many commercial X-ray detectors (Si, α-Se) and several times higher than other reported inorganic perovskite materials (CsPbBr3 quantum dots, Cs2AgBiBr6).