Investigating the efficiency of InGaN p-n-p-n homojunction solar cells

Abstract This research investigates the development of a novel p-n-p-n homostructure solar cell, through semiconductor simulations using the Nextnano software. InGaN was used as a model system in order to achieve a bandgap with optimized efficiency for a p-n homojunction solar cell. By increasing the uniform doping concentration from 1.5*10 16 cm −3 to 1.5*10 17 cm −3 , the open circuit voltage ( V oc ) increased while the short-circuit current density ( J sc ) decreased, as expected in simple p-n junctions. The p-n-p-n structure achieved a peak efficiency of 32.91% at a doping level of 6.5*10 16 cm −3 , a ~7% improvement over a conventional p–n junction’s 25.31% efficiency (International Journal of Photoenergy - 2015 - Mesrane - Design and Simulation of InGaN p‐n Junction Solar Cell.pdf, (n.d.)). For higher uniform doping levels, above ~7.5*10 16 cm −3 , the turn-on of the I-V curves become sharp, suggesting that the device transforms into a bistable switch like a thyristor rather than a conventional solar cell leading to a highest efficiency of 48.68% for a doping concentration of 1.5*10 17 cm −3 . Graphical abstract