Controllable Growth of Lead-Free All-Inorganic Perovskite Nanowire Array with Fast and Stable Near-Infrared Photodetection

Low-dimensional all-inorganic metal halide perovskites have been demonstrated as excellent building blocks for high-performance optoelectronic devices. Although many progresses have been achieved in low-dimensional all-inorganic perovskites, the substitution of toxic Pb is urgent for further optoelectronic applications. Here, we present the growth of lead-free all-inorganic CsSnX3 (X = Cl, Br, and I) perovskite nanowire (NW) arrays on a mica substrate by a solid-source chemical vapor deposition method. All of the lead-free all-inorganic CsSnX3 perovskite NW arrays epitaxially grow on the mica substrate to form equilateral triangles. The band gaps of the as-prepared CsSnX3 perovskite NW arrays decrease from 1.84 to 1.34 eV with X changes from Br to I. The high crystallinity is confirmed by the strong photoluminescence (PL) emission peaks and uniform two-dimensional PL mapping images. In the end, the as-prepared high-quality CsSnI3 perovskite NW array is then configured into a near-infrared photodetector for the first time, exhibiting fast rise and decay time constants of 83.8 and 243.4 ms, respectively. All of the results present an important advance in the field of low-dimensional all-inorganic perovskites.