Design and Modeling of High-Efficiency GaAs -Nanowire Metal-Oxide-Semiconductor Solar Cells beyond the Shockley-Queisser Limit: An NEGF Approach

• DOI: 10.1103/physrevapplied.15.024055
• Publication Date: 2021-02-23T17:34:46Z
• Authors: Subhrajit Sikdar; Basudev Nag Chowd...; Sanatan Chattopad...
• Keywords: Quantum Efficiency

The present work proposes a $\mathrm{Ga}\mathrm{As}$-nanowire-based vertical metal-oxide-semiconductor (MOS) solar cell of quantum scale to achieve very high efficiency beyond the Shockley-Queisser (SQ) limit. Photogeneration and carrier transport in such devices are analytically modeled by adopting nonequilibrium Green's function formalism based on second quantization field operators for incident photons generated photocarriers. study suggests that utilization photogenerated light heavy holes harvest energy is capable providing significantly higher power conversion above SQ Such superior achieved due resonance photon modes with gap between three-dimensional-quantized electron states two-dimensional-quantized hole subbands. efficiency, along other relevant solar-cell-performance parameters, as open-circuit voltage, short-circuit current, fill factor, external responsivity, observed depend nanowire diameter top-oxide thickness, which, turn, controls effect MOS devices. results show 50% can be tosylate-modified poly(3,4-ethylenedioxythiophene) (PEDOT-Tos)/${\mathrm{Si}\mathrm{O}}_{2}/\mathrm{Ga}\mathrm{As}$-nanowire combination oxide thickness range 18--14 nm 4--2 nm, respectively. Thus, proposed device scheme offers an alternative design route next-generation cells engineering effect.