Fig. 2: Comparison of GaN facet properties.

Overlaid topography-potential three-dimensional spatial maps of a as-grown GaN NWs and b Faceted-GaN NWs. c PEIS curves of GaN/Si and the Faceted-GaN/Si photoelectrode in 0.5 M H2SO4 (pH = 0). d Comparison of the ECSA of GaN/Si and Faceted-GaN/Si estimated from the Cdl values. e Density of states of GaN (10\(\bar{1}\bar{1}\)) and GaN (000\(\bar{1}\)). f Electron localization function analysis of GaN (10\(\bar{1}\bar{1}\)) and GaN (000\(\bar{1}\)).