Patterned Lead Halide Perovskite Crystals Fabricated by Microstructured Templates

Lead halide perovskite crystals have been widely used in solar cells, lasers, organic light-emitting diodes, piezoelectric sensors, etc. due to their high carrier mobility, large light absorption coefficients, and long carrier diffusion lengths. So far, much effort has been devoted to the fabrication of lead halide perovskite crystals by means of a solution process and physical methods. In some application domains, the lead halide perovskite crystals, as lasers or devices, for example, require a regular micropatterned structure in order to achieve arrays with almost identical optical or electronic modes. Concomitantly, patterned structures can further optimize the properties of perovskite crystals in their related optoeletronic devices. Therefore, how to fabricate micropatterned lead halide perovskite crystal is one of the hottest research topics in the past few years. Among various kinds of strategies, a combination of templates and wetting discrepancy has been demonstrated to be a simple but robust method, to obtain perovskite crystals with regular arrays and excellent properties. The common selected template materials are silicon, polydimethylsiloxane (PDMS), anodized aluminum oxide (AAO), and photoresist. This review provides insight into the fabrication of patterned lead halide perovskite crystals by using templates composed by the materials stated above and intelligently controlling wetting discrepancy. More importantly, we briefly discuss the key factors and challenges during the pattern process. Finally, the relationship among these templates is discussed, which will shed light on the low-cost fabrication of stable, high-quality perovskite crystals for new applications.