A first-principles study of the effects of different Al constituents on Ga1-xAlxN nanowires

In order to investigate the influences of different Al constituents onGa(1-x)Al(x)N nanowires, the formation energy, stability, band structure, densities of states and optical properties of Ga1-xAlxN nanowires with different Al constituents are calculated using first-principles plane-wave ultrasoft pseudopotential method. Results show that nanowires become more stable with increasing Al constituent. Bandgap of nanowires increases as the Al constituent increases but with a lower amplification compared with bulk Ga1-xAlxN. The peaks of static dielectric constants show a decreasing trend and move towards high-energy side as Al constituent increases. The absorption of Ga(1-x)Al(x)Nnanowires shows an interesting phenomenon that it firstly increases and then decreases slightly as the Al constituent increases. Reflectivity of nanowires is much smaller than that of the bulk. The optical properties of nanowires show a blueshift effect as Al composition increases. According to these calculations, it is found that Ga1-xAlxN nanowires are appropriate to be applied into photoelectric detecting materials by adjusting the Al constituent of Ga1-xAlxN nanowires.