Catalyst-Free Heteroepitaxial MOCVD Growth of InAs Nanowires on Si Substrates

We report the systematic study of catalyst-free syntheses of InAs nanowires on Si substrates with various growth parameters and surface treatments. Nanowire morphology and crystal structure were studied using scanning electron microscopy and transmission electron microscopy. High-resolution cross-sectional transmission electron microscopy studies reveal heteroepitaxy of InAs[111] nanowires on Si(111) substrate with clean and sharp interface. Single nanowire field-effect transistor measurements of InAs nanowires under optimal growth conditions indicate a typical electron concentration of 10 18 –10 19 cm –3 and mobility of around 1000 cm 2 /V·s. III/V on Si devices with InAs nanowire array on p-Si show a broadband photodetection up to wavelength of 3.5 μm.