Engineering the Optical Properties of Eco‐Friendly CuGaS<sub>2</sub>/ZnS and CuGaInS<sub>2</sub>/ZnS Core/Shell Quantum Dots for High‐Performance Tandem Luminescent Solar Concentrators
Huaqian Zhi, Xin Tong, Yimin You, Ali Imran Channa, Xin Li, Jiang Wu, Gurpreet Singh Selopal, Zhiming M. Wang
Abstract
Herein, highly luminescent eco‐friendly CuGaS 2 /ZnS (CGS/ZnS) and CuGaInS 2 /ZnS (CGIS/ZnS) core/shell quantum dots (QDs) are rationally prepared for luminescent solar concentrator (LSC) application. It is demonstrated that the optical properties of these core/shell QDs can be tailored by engineering the ZnS shell thickness, leading to large Stokes shifts and high‐photoluminescence quantum yields up to 94.6%. As‐synthesized core/shell QDs with optimized optical properties are employed to fabricate LSCs (5 × 5 × 0.5 cm 3 ) using glasses as waveguides, wherein the individual CGS/ZnS and CGIS/ZnS QD‐based LSCs, respectively, exhibit an optical efficiency ( η opt ) of ≈3.26% and 6.53% under AM1.5G illumination (100 mW cm −2 ). Remarkably, a tandem QDs‐LSC integrated via vertical stacking of the top yellow‐emitting CGS/ZnS QDs‐LSC and bottom red‐emitting CGIS/ZnS QDs‐LSC delivers an optical efficiency ( η opt ) as high as 9.94%, which is, respectively, ≈3 and 1.5 times higher than the individual QDs‐LSCs and is comparable to various best‐reported QDs‐LSCs. The results indicate that environment‐benign I–III–VI 2 core/shell QDs with engineered optical properties and LSC architectural design are promising to develop future cost‐effective and high‐performing building‐integrated photovoltaics.