Investigation of quantum dot luminescent solar concentrator single, double and triple structures: A ray tracing simulation study

Abstract

Quantum dot based luminescent solar concentrators (QDLSCs) are a special class of transparent photovoltaics (TPV), especially suited for building integrated photovoltaics (BIPV). Photons are absorbed by luminescent species in a waveguide and emitted at a red-shifted wavelength. Due to total internal reflection, these photons are absorbed by the solar cells attached to the sides. Successful deployment requires high conversion efficiency and high transparency, which are contradictory requirements. We have performed Monte-Carlo ray tracing simulations to investigate single, double, and triple QDLSCs and have assessed their optical and electrical performance. To this end, eight different semiconductor quantum dot materials have been used with various absorption and emission properties, and Stokes’ shift. Device efficiency is analyzed for different average visible transmission (AVT) values, thus considering the human photopic response. The range of luminescent quantum efficiencies (30%–70%) leads to maximum efficiency of 2% for a single QDLSC, 2.4% for a double, and 2.7% for a triple structure, at high transparency and good color rendering index. Further improvements are possible towards 5% at high transparency with near-unity quantum efficiencies.