Effect of Strain-Modulated Multiple Quantum Wells on Carrier Dynamics and Spectral Sensitivity of III-Nitride Photosensitive Devices

Abstract

In III-Nitride planar photosensitive devices (PSDs), proper engineering in polarization charges (PCs) are required in order to reduce detrimental effects on the devices. In this work, piezo-phototronic effects of PSDs are explored, giving more emphasis on photovoltaic application. The polarization effects of GaN/In x Ga1– x N multiple quantum wells on planar solar cell with {000-1} or {0001} as one of the facets are intensively studied through numerical simulations. Analysis of PCs both in simulation and theoretical model at different facets of solar cell with different ‘In’ compositions are considered carefully. It is observed that planar PSDs with reversed polar {000-1} facet is good enough to enhance the carrier dynamics of solar cell in quasi neutral region as compared to normal polarization {0001} facet. This numerical study provides an innovative aspect of implementation of fundamental device physics with respect to recent growth techniques in order to realize the application of III-Nitride PSDs towards photovoltaic applications. The effect of GaN/In x Ga1– x N layer with different ‘In’ compositions in all crystallographic orientations of planar solar cell are also discussed. A conversion efficiency of 21% with 74% fill factor is achieved from strain modulated four quantum well based solar cell considering 10% of ‘In’ content under one sun AM1.5G illumination.