The synthesis of certain perovskite single crystals (SCs), including CH3NH3PbI3, through asymmetric crystallization is difficult, mainly because of the large difference in solubility of the precursors and/or the intrinsic nonpreference for growth in a direction along the substrate. Herein, an effective method is reported, seeded space-limited inverse-temperature crystallization (SSLITC), for growing CH3NH3PbI3 SC plates having micrometer-scale diameters. In this process, a seed CH3NH3PbI3 crystal is incorporated within a confined space to promote crystallization. Crystal plates having lateral dimensions of up to 2 mm are grown successfully. These SCs and a polymer conductive glue to fabricate perovskite solar cells on flexible substrates are used. One such device exhibits a maximum external quantum efficiency of 96%, a high photocurrent of 22 mA cm−2, and a power conversion efficiency of greater than 4%. In addition, a device prepared without any encapsulation exhibits reasonable stability, suggesting a promising future for SC-based perovskite solar cells. It is anticipated that the SSLITC method proposed herein could open up new avenues for synthesizing various types of organic/inorganic perovskite SCs for applications in modern electronics.
- single crystals