Ligand assisted growth of perovskite single crystals with low defect density

A low defect density in metal halide perovskite single crystals is critical to achieve high performance optoelectronic devices. Here we show the reduction of defect density in perovskite single crystals grown by a ligand-assisted solution process with 3-(decyldimethylammonio)-propane-sulfonate inner salt (DPSI) as an additive. DPSI ligands anchoring with lead ions on perovskite crystal surfaces not only suppress nucleation in solution, but also regulate the addition of proper ions to the growing surface, which greatly enhances the crystal quality. The grown CH3NH3PbI3 crystals show better crystallinity and a 23-fold smaller trap density of 7x10(10)cm(-3) than the optimized control crystals. The enhanced material properties result in significantly suppressed ion migration and superior X-ray detection sensitivity of CH3NH3PbI3 detectors of (2.60.4)x10(6)mu CGy(-1)air cm(-2) for 60kVp X-ray and the lowest detectable dose rate reaches (5.0 +/- 0.7)nGys(-1), which enables reduced radiation dose to patients in medical X-ray diagnostics. The performance of a metal halide perovskite single crystal is governed by the defect density. Here, the authors report a high quality single crystal perovskite grown by a ligand-assisted solution process with DPSI achieving 23-fold smaller trap density than that without DPSI.

Automated summary

The defect density in metal halide perovskite single crystals plays a critical role in achieving high-performance optoelectronic devices. In this study, the authors demonstrate a significant reduction in defect density in perovskite single crystals grown using a ligand-assisted solution process with DPSI as an additive, resulting in improved crystal quality and enhanced X-ray detection sensitivity.