Study of light-trapping enhanced quantum dot solar cells based on electrical and optical numerical simulations

We study InAs/GaAs quantum dot solar cells exploiting light trapping approaches to enhance the interband light harvesting efficiency of quantum dots. A realistic thin-film structure including a nanostructured anti-reflection coating and a planar reflector is investigated both from the optical and electrical standpoint, based on finite difference time domain electromagnetic simulations and on quantum-dot-aware transport simulations. The photovoltaic efficiency of quantum dot solar cells and reference bulk cells is analyzed for various configurations, from the single-pass -wafer-based- one to the thin-film one approaching the ideal Lambertian limit. We show that light-trapping enhancement, combined with QD selective doping, may allow the quantum dot cell to achieve photovoltaic efficiency higher than its bulk counterpart.