Exploring Anisotropy on Oriented Wafers of MAPbBr₃ Crystals Grown by Controlled Antisolvent Diffusion

The emergence of organic–inorganic halide perovskites has reformed the research status of optoelectronics to a great extent. The bulk single crystals of halide perovskite, which in theory reflect the intrinsic physical properties of the material, are however hard to integrate into functional devices. Just as in the case that silicon wafers have revolutionized modern industries including electronics and solar cells, the availability of perovskite crystal wafers may pave the way to functional devices. Here we designed a new settled temperature and controlled antisolvent diffusion system to precisely control all key factors that affect the supersaturation metastable zone during the crystal growth process, to grow MAPbBr3 single crystals more than 50 mm in size. Second, we fabricated MAPbBr3 single crystal wafers with different orientations, specifically, the (100), (010), (001), (110), and (111) wafers, with high crystalline quality (half-peak width of rocking curve of 60–100 arc sec). Some key parameters were measured and compared on the wafers, where the results hint that anisotropy of carrier transport may exist for this pseudocubic structure. We hope the availability of oriented single-crystal wafers can provide more scientists the materials and devices to clarify the debatable physicochemical properties and to integrate the wafers as active layers or substrates in optoelectronic devices