Two-dimensional Transition Metal Dichalcogenide Heterobilayer Emitters for Luminescent Solar Concentrator Photovoltaics

Abstract

Luminescent solar concentrator devices offer potential pathways for reductions in photovoltaic system soft costs through module integration within traditional building envelopes. However, to achieve competitive power conversion efficiency performance for such concentrators, near-unity luminophore photoluminescence quantum yield, large absorption/emission spectral separation (i.e., Stokes shift), and efficient photon trapping within the optical waveguide structure must all be attained. Within the past decade, tremendous research efforts on transition metal dichalcogenide monolayers have achieved near-unity quantum yields. Moreover, previous work shows how stacking two such monolayers together to form a heterobilayer enables highly anisotropic, dipole-like far-field emission of radiatively recombined excitons. Here, we computationally demonstrate, as a proof of concept, the performance of a single-junction luminescent solar concentrator device employing transition metal dichalcogenide heterobilayers as the active luminophore species. We model such a device with two variations of such heterobilayers (MoS₂/WS₂, MoS₂/WSe₂). Using an experimentally validated Monte Carlo ray-trace model, we sweep across the relevant device parameter space with power conversion efficiency as our primary figure of merit. We find that for a modest geometric gain of 10, an optical density of 3, and PLQYs approaching unity, the photovoltaic module reaches a power efficiency of 3.8% for both MoS₂/WS₂ and MoS₂/WSe₂.