High-quality InAs/InSb nanowire heterostructures grown by metal-organic vapor-phase epitaxy.

Recently, semiconducting nanowires have attracted much interest due to their advantageous physical properties and a wide range of potential applications in electronics, optoelectronics, and biosensors. High-quality compound nanowire heterostructures have been grown using various techniques, including chemical-beam epitaxy (CBE) and metal–organic vapor-phase epitaxy (MOVPE), with both methods producing sharp interfaces. To date, most studies have concentrated on ‘‘classic’’ III–V semiconductors, such as InAs, InP, GaAs, GaP, and nitride nanowires. Antimonycontaining nanowires would extend the range of usable materials in these heterostructures and devices. InSb is the III–V semiconductor with the narrowest bandgap (0.17 eV) and the largest bulk electron mobility ( 7.7 10 cm V 1 s ); it also has a high thermoelectric figure of merit (0.6). This material is therefore extremely interesting for applications in high-speed and low-power electronics, infrared optoelectronics, quantum-transport studies, and thermoelectric power generation. Despite all of these promising advantages, very few studies on InSb nanowires have been reported. There have so far been no reports on InSb-containing nanowire heterostructures. Moreover, due to the large lattice mismatch between InAs and InSb (7%), no combination of these materials has been reported using planar growth. In this Communication, we demonstrate for the first time growth of high-quality InAs/InSb heterostructure nanowires.