Laser-enabled low-thermal-budget growth of vertically aligned InP nanowires for monolithic optoelectronic integration

Monolithic integration of direct-bandgap III–V semiconductors with electronic and photonic circuitry is constrained by the high thermal budgets of conventional epitaxy and by the transfer and alignment steps required for solution-synthesized nanomaterials. Here, we demonstrate a laser-induced solution–liquid–solid (Laser–SLS) strategy for the direct, transfer-free growth of vertically aligned indium phosphide (InP) nanowires on substrates under a low global thermal budget. Focused 532 nm pulsed-laser irradiation couples to liquid indium catalyst droplets, which act simultaneously as nanoscale reaction sites and localized photothermal hot spots. The resulting confined thermal field promotes precursor activation, phosphorus incorporation, catalyst wetting, and InP crystallization at the catalyst–substrate interface while limiting substrate-wide heating. Vertically aligned, single-crystalline InP nanowires are grown directly on InP and germanium substrates in 2 min, and vertical nanowire growth is also achieved on amorphous quartz, demonstrating the compatibility of the method with both homogeneous and heterogeneous platforms. The as-grown InP nanowires show measurable photoresponse, highlighting the potential of Laser–SLS as a transfer-free, low-thermal-budget route for incorporating vertically aligned III–V active elements into future three-dimensional silicon photonic and heterogeneous optoelectronic systems.