Bandgap engineering of GaxZn1-xO nanowire arrays for wavelength-tunable light-emitting diodes

Wavelength-tunable light-emitting diodes (LEDs) of GaxZn1-xO nanowire arrays are demonstrated by a simple modified chemical vapor deposition heteroepitaxial growth on p-GaN substrate. As a gallium atom has similar electronegativity and ion radius to a zinc atom, high-level Ga-doped GaxZn1-xO nanowire arrays have been fabricated. As the xvalue gradually increases from 0 to 0.66, the near-band-edge emission peak of GaxZn1-xO nanowires shows a significant shift from 378 nm (3.28 eV) to 418 nm (2.96 eV) in room-temperature photoluminescence (PL) measurement. Importantly, the electroluminescence (EL) emission of GaxZn1-xO nanowire arrays LED continuously shifts with a wider range (approximate to 100 nm), from the ultraviolet (382 nm) to the visible (480 nm) spectral region. The presented work demonstrates the possibility of bandgap engineering of low-dimensional ZnO nanowires by gallium doping and the potential application for wavelength-tunable LEDs.