Synchrotron radiation researcher Ziyun Huang shows how to grow free-standing perovskite nanowires ligand-free. A controlled nitrogen flow dramatically improves yield, and in situ microscopy visualizes the growth dynamics.
Metal halide perovskite nanowires are widely studied due to their unique electronic and optical characteristics, making them promising for light emitting and detection applications. We developed a ligand-free method to grow vertically aligned free-standing CsPbBr3 nanowires from anodized aluminum oxide nanopore substrates. Here, we investigate the growth process using in situ microscopy with ultraviolet and visible light excitation, revealing a highly dynamic process with pronounced fluorescence at locations where high-density free-standing nanowires could be found. The yield of the growth is strongly improved by using a growth reactor with controlled N2 flow, increasing from 17 to 60%. We systematically investigated the growth dependence on the temperature and N2 flow rate and identified optimal parameters at 70 °C and 0.8 L/min, respectively. The improved control over the growth of free-standing nanowires expands opportunities for their integration into optoelectronic devices.
Controlled Ligand-Free Growth of Free-Standing CsPbBr3 Perovskite Nanowires