Dual-mechanism light management in luminescent solar concentrators enabled by conical emitter arrays

Abstract

Luminescent solar concentrators (LSCs) are promising candidates for building-integrated photovoltaics, but their performance is fundamentally constrained by escape-cone losses associated with isotropic luminescence. Here, we report a conical emitter array LSC that overcomes these limitations through a dual light-management mechanism combining directional emission control and reflective light redirection. High-quality Mn-doped CsPbCl₃ nanocrystals (NCs), selected for their enhanced stability and large Stokes shift, are assembled into micrometer-scale conical emitter arrays via a casting-assisted blade-coating strategy filling process and embedded in a polydimethylsiloxane waveguide. Owing to the anisotropic geometry of the conical emitters, the angular distribution of luminescence is reshaped to suppress escape-cone losses, enabling edge-collection efficiencies exceeding the theoretical trapping limit of planar LSCs. In parallel, refractive-index contrast at the emitter–matrix interface induces prism-like reflection of incident light, redirecting a fraction of non-collimated solar photons toward the device edges. As a result, a 5 × 5 × 0.5 cm³ LSC prototype achieves an overall optical efficiency of 6.5% and a power conversion efficiency (PCE) of 2.76%, representing an ∼20% improvement over conventional LSCs with randomly dispersed NCs. This scalable conical emitter array architecture provides a viable strategy for surpassing planar LSC limits and advancing high-performance, transparent photovoltaics for building integration.