Direct band gap GaP nanowires predicted through first principles

作者：Santos Charley B E^*; Schmidt T M

来源：Journal of Applied Physics, 2010, 108(10): 103715.

DOI：10.1063/1.3511340

GaP nanowire, a potential material for new devices where optical and electronic applications can be merged, suffers some limitations because it presents indirect band gap. Using first principles calculations we demonstrate that, due to confinement effects, the band gap not only is enlarged when in a nanowire form, but can be transformed to a direct band gap semiconductor nanowire, just by reducing the nanowire diameter to few nanometers. This transition to a direct band gap is obtained for (111) oriented GaP nanowires but not for [110] oriented nanowires. The effects of surface states which can alter the band gap have been studied with hydrogen saturation and an oxide cap layer on the surface of the GaP nanowire. The results show that, while the hydrogen is a perfect passivator, the GaP/Ga(2)O(3) heterojunction presents a small conduction band offset but keeps direct band gap (111) oriented GaP nanowires.

• 出版日期2010-11-15