Ultra-high-efficiency luminescent solar concentrator using superimposed colloidal quantum dots

The world energy crisis, as well as global warming, has intensified an urgent need for renewable energies. Solar radiation can be converted to electricity by solar cells readily; however, the high cost of photovoltaic systems has hindered its worldwide commercialization. Also, the solar cells cannot be integrated directly to skyscrapers. Therefore, luminescent solar concentrators have been developed. Here, we have proposed a novel and exciting structure for LSCs based on four different groups of QDs (generally superposition of QDs) with different sizes and materials to absorb photons from sunlight ranging from ultraviolet to near-infrared and then guide re-emitted photons to edge of LSC, which culminate in capturing photons by solar cells. We designed the QDs such that the absorption and emission spectra have minimum overlap leading to limited reabsorption losses. A Monte-Carlo ray-tracing simulation has been developed to model and evaluates the effectiveness of the proposed device. Then, we have optimized the QD’s concentration and LSC geometry to achieve maximum optical efficiency. For different quantum yields ranging from 0.4 to 1, we have obtained theoretically super high optical efficiency of 11–31%. The optimization results show a 67.8% enhancement in optical flux gain leading to 3.72-times more concentrated photon flux demonstrating our device’s commercialization potential. Besides, total absorbed photons, transparency, and ultimate fate of all photons were calculated. Finally, the proposed idea can be used to introduce a high-efficiency solar concentrator while extending the coverage of solar cells to make green energy.