Inch‐Size Single Crystal of a Lead‐Free Organic–Inorganic Hybrid Perovskite for High‐Performance Photodetector

Large‐size crystals of organic–inorganic hybrid perovskites (e.g., CH 3 NH 3 PbX 3 , X = Cl, Br, I) have gained wide attention since their spectacular progress on optoelectronic technologies. Although presenting brilliant semiconducting properties, a serious concern of the toxicity in these lead‐based hybrids has become a stumbling block that limits their wide‐scale applications. Exploring lead‐free hybrid perovskite is thus highly urgent for high‐performance optoelectronic devices. Here, a new lead‐free perovskite hybrid (TMHD)BiBr 5 (TMHD = N,N,N,N ‐tetramethyl‐1,6‐hexanediammonium) is prepared from facile solution process. Emphatically, inch‐size high‐quality single crystals are successfully grown, the dimensions of which reach up to 32 × 24 × 12 mm 3 . Furthermore, the planar arrays of photodetectors based on bulk lead‐free (TMHD)BiBr 5 single crystals are first fabricated, which shows sizeable on/off current ratios (≈10 3 ) and rapid response speed (τ rise = 8.9 ms and τ decay = 10.2 ms). The prominent device performance of (TMHD)BiBr 5 strongly underscores the lead‐free hybrid perovskite single crystals as promising material candidates for optoelectronic applications.