Performance Enhancement of Double Quantum Well Solar Cell by Strain-Modulated Piezo-Phototronics Effect

In Quantum Well (QW) solar cells, modulation of in built piezo-phototronics mechanism are required in order to enhance performance of solar cell. In this work, the polarization effects of $\mathrm{GaN}/\mathrm{In}_{x}\mathrm{Ga}_{1-x}\mathrm{N}$ multiple quantum well planar solar cell with different orientational dependent facets are intensively studied through numerical simulations. Analysis of polarization charges both in simulation and theoretical at different facets of solar cell with different ‘In’ compositions are considered carefully. It is observed that QW solar cell with reversed polar {000-1} facet is good enough to enhance the collection efficiency of solar cell in quasi neutral region as compared to normal polarization {0001} facet. This numerical study provides a different aspect of engineering the fundamental device physics with respect to recent growth techniques in order to realize the application of III-Nitride nanowires towards photovoltaic applications. The effect of $\mathrm{GaN}/\mathrm{In}_{x}\mathrm{Ga}_{1-x}\mathrm{N}$ layer with different ‘In’ compositions in all crystallographic orientations of nanowire solar cells are also discussed. A conversion efficiency of more than 16% with 76% fill factor and 82% quantum efficiency is achieved from strain modulated dual QW based solar cell considering 10% of ‘In’ content under one Sun AM1.5 illumination.