2D Halide Perovskite Growth within Interlayer Spacings of van der Waals Substrates

Two-dimensional hybrid organic-inorganic perovskites (2D-HOIPs) have been extensively researched for use in solar cells as well as optoelectronic devices over the past few years. While various solution-based techniques have been explored and established for growth of 2D-HOIPs in polycrystalline and bulk form, studies of their growth in single-crystalline thin film forms have been limited. Here, we report a solution-based method for growth of 2D-HOIPs using muscovite mica as a van der Waals substrate that yields millimeter scale perovskite flakes. Interestingly, the grown 2D-HOIP flakes lie embedded within interlayer spacings of muscovite mica. We find that such 2D-HOIP flakes buried in mica demonstrate enhanced photostability in comparison to conventional 2D-HOIP flakes. Such liquid phase growth in the interlayer spacings of van der Waals substrates opens a new avenue for developing novel materials structure for designing high-performance optoelectronic devices.