General Trends in the Performance of Quantum Dot Luminescent Solar Concentrators (LSCs) Revealed Using the “Effective LSC Quality Factor”
Kıvanç Güngör, Jun Du, Victor I. Klimov
Abstract
CuInSe2–xSx (CISeS) quantum dots (QDs) are promising materials for implementing luminescent solar concentrators (LSCs). Their benefits include near-infrared (NIR) absorption onset, efficient NIR photoluminescence (PL), and low reabsorption losses stemming from the intragap character of their emission. To streamline optimization of CISeS QDs for LSC applications, we develop an analytical model which allows us to relate the absorptance-optimized external quantum efficiency (EQE) to the QD PL quantum yield (QY) and the “effective LSC quality factor”, ⟨Q⟩, used to characterize the interplay between the QD’s light-harvesting ability and self-induced reabsorption losses. Specifically, we show that the peak EQE can be approximated by the product of QY and log(⟨Q⟩), the conclusion validated by the numerical analysis of 47 QD samples. Interestingly, according to the modeling, the QDs with ⟨Q⟩ = 10.5 and QY = 78% were expected to yield the highest EQE in the surveyed group (11.8% for LSC dimensions 9.5 × 9.5 × 0.77 cm3). This prediction was confirmed by experimental measurements that indicated an EQE of 11.7% for this particular sample. We anticipate that the developed formalism will simplify optimization of CISeS QDs for LSC applications and facilitate further developments in the LSC area.