Spontaneous and piezo-phototronics effect on geometrical shape of III-Nitride wurtzite nanowires for high efficiency photovoltaic applications

In this study, the influence of spontaneous and piezo-phototronic effect on the performance of hexagonal and triangular III-Nitride nanowire (NW) photovoltaic devices are investigated. The effect of stress/strain distribution on band structure of GaN/InxGa1-xN/GaNcore/shell/shell NW solar cell with hexagonal and triangular geometrical shape are also intensively investigated by numerical calculations. It is observed that NW solar cells possess a non-uniform pattern of polarisation charges (PCs) due to complex distribution of strain and stress parameters depending upon growth orientations of NWs. Effect of PCs, especially due to piezo-phototronic effect on the polar, semi-polar and non-polar planes of NW having Miller-Bravais indices of {000-1}, {1-101} and {1-100} are discussed in detail, respectively. This numerical study not only provides the basic theoretical understanding about the spontaneous and piezo-phototronic effect on III-Nitride solar cell but also assists to obtain most optimised geometrical design to achieve high performance NW solar cell.