Process for wide bandgap semiconductor nanowires obtaining on narrow bandgap semiconductor substrate

Abstract

Herein, we propose the manufacture of wide bandgap (Eg) semiconductor nanowires (e.g. from Ga2O3 with Eg = 4.9 eV, or In2O3 with Eg ~ 3 eV) on narrow bandgap semiconductor support with good thermal conductivity () (e.g. GaAs with Eg = 1.44 eV and  = 52 W / m•K or InP with Eg = 1.34 and  = 68 W / m•K), and the diameter of the nanowires varies in the range from 50 nm to 500 nm. The advantages of the proposed process over other already existing processes consists in the possibility of forming wide bandgap semiconductor nanowire networks on narrow bandgap semiconductor support with good thermal conductivity through simple, accessible and cost-effective technologies. In the first step, the GaAs or InP semiconductor nanowires are obtained on the surface of bulk semiconductor substrate via electrochemical etching of bulk substrates. Subsequent treatment of GaAs nanowires at 900 °C for 60 minutes in a low oxygen content atmosphere (3%) leads to the transformation of GaAs (InP) nanowires into Ga2O3 (In2O3) nanowires, accordingly to the EDX and XRD analysis. The technological parameters of thermal treatment are optimized in such a way that bulk semiconductor substrate is not oxidized.