An eco-friendly luminescent solar concentrator with high photon transport efficiency based on Bi-doped Cs2Na0.6Ag0.4InCl6 quantum dots

Luminescent solar concentrators (LSCs) serving as potential energy-conversion units have received great attention in building-integrated photovoltaics (BIPVs). However, the main challenge for BIPV-used LSCs is to maintain a high transparency while improving its photo-electric performance. In this work, we fabricate a flexible LSC by incorporating Bi-doped Cs2Na0.6Ag0.4InCl6 double perovskite (DP) QDs into polydimethylsiloxane (PDMS). The as-synthesized QDs show a large Stokes shift and broadband orange emission originating from the recombination between the localized states of [BiCl6] and [AgCl6] octahedra. The resultant LSC based on the above QDs exhibits a high internal quantum efficiency of up to 34.42%, which is relatively higher than that of other reported QD-based LSCs. More attractively, the average visible transmittance of the LSC remains 91.55%. By attaching a Si PV cell along the edge of the LSC, the optimal power conversion efficiency (PCE) and optical efficiency (ηopt) of the LSCs of 2.56% and 2.57%, respectively, can be reached under the irradiation of a solar simulator. In addition, the LSC presents good photostability after 80 h of xenon lamp irradiation. Therefore, we anticipate that the lead-free DP QD-based LSCs may provide a promising direction for high-efficiency transparent LSCs.