Acquiring Bulk Photovoltaic Effect in One-Dimensional Sn-Based Perovskite Single Crystals by Nonlinear Organic Diamine

Low-dimensional metal halide perovskites with noncentrosymmetric crystal structure provides opportunities of bulk photovoltaic effect (BPVE), which is expected to promote efficiency of photovoltaic devices by strengthening the build-in potential and carrier transport. Up to now, perovskite materials with BPVE usually contain toxic lead ions, which severely limits their practical application. Herein, one-dimensional (1D) Sn-based perovskites MDASn2I6 (MDA = 4,4′-methylenedianiline) with noncentrosymmetric structure by selecting an organic diamine with nonlinear molecular configuration are reported. The directional arrangement and inherent polarity of the MDA molecules endow the as-grown 1D single crystals with noncentrosymmetric crystal structure and spontaneous polarization. Photodetectors with symmetrical electrodes show switchable photovoltage and current–voltage curves, demonstrating the existence of BPVE. Finally, the crystal properties under high pressure, at which the crystals exhibit enhanced carrier transport and broader absorption range, are investigated, showing the potential application in extreme conditions. This work provides a novel strategy for the design and preparation of noncentrosymmetric lead-free perovskite single-crystal materials, which will promote green fabrication of perovskite single-crystal optoelectronic devices.