posted on 2022-12-29, 13:06authored byYou Meng, Yuxuan Zhang, Zhengxun Lai, Wei Wang, Weijun Wang, Yezhan Li, Dengji Li, Pengshan Xie, Di Yin, Dong Chen, Chuntai Liu, SenPo Yip, Johnny C. Ho
Converting vapor precursors to solid nanostructures via
a liquid
noble-metal seed is a common vapor deposition principle. However,
such a noble-metal-seeded process is excluded from the crystalline
halide perovskite synthesis, mainly hindered by the growth mechanism
shortness. Herein, powered by a spontaneous exothermic nucleation
process (ΔH < 0), the Au-seeded CsPbI3 nanowires (NWs) growth is realized based on a vapor–liquid–solid
(VLS) growth mode. It is energetically favored that the Au seeds are
reacted with a Pb vapor precursor to form molten Au–Pb droplets
at temperatures down to 212 °C, further triggering the low-temperature
VLS growth of CsPbI3 NWs. More importantly, this Au-seeded
process reduces in-bandgap trap states and consequently avoids Shockley–Read–Hall
recombination, contributing to outstanding photodetector performances.
Our work extends the powerful Au-seeded VLS growth mode to the emerging
halide perovskites, which will facilitate their nanostructures with
tailored material properties.