Direct Growth of Light-Emitting III-V Nanowires on Flexible Plastic Substrates.

Semiconductor nanowires are routinely grown on high-priced crystalline substrates as it is extremely challenging to grow directly on plastics and flexible substrates due to high-temperature requirements and substrate preparation. At the same time, plastic substrates can offer many advantages such as extremely low price, light weight, mechanical flexibility, shock and thermal resistance, and biocompatibility. We explore the direct growth of high-quality III-V nanowires on flexible plastic substrates by metal-organic vapor phase epitaxy (MOVPE). We synthesize InAs and InP nanowires on polyimide and show that the fabricated NWs are optically active with strong light emission in the mid-infrared range. We create a monolithic flexible nanowire-based p-n junction device on plastic in just two fabrication steps. Overall, we demonstrate that III-V nanowires can be synthesized directly on flexible plastic substrates inside a MOVPE reactor, and we believe that our results will further advance the development of the nanowire-based flexible electronic devices.

InAs-Nanowire-Based Broadband Ultrafast Optical Switch.

Due to their tunable optical properties with various shapes, sizes, and compositions, nanowires (NWs) have been regarded as a class of semiconductor nanostructures with great potential for photodetectors, light-emitting diodes, gas sensors, microcavity lasers, optical modulators, and converters. Indium arsenide (InAs), an attractive III-V semiconductor NW with the advantages of narrow bandgap and large electron mobility, has attracted considerable interest in infrared optoelectronic and photonic devices. Here, we studied the ultrafast carrier dynamics and nonlinear optical responses of InAs NWs ranging from 1.0 to 2.8 µm and demonstrated the InAs-NW-based ultrafast broadband optical switch for passively Q-switching in all-solid-state laser systems. Furthermore, we achieved ultrafast optical modulation for laser mode-locking at 1.0 µm, paving the way for their applications in the field of ultrafast optics. These exotic optical properties indicate that InAs NWs have significant potential for various optoelectronic and photonic devices, especially in the mid-infrared wavelength range.