CuInS₂ Quantum Dots with Thick ZnSe_xS_1–x Shells for a Luminescent Solar Concentrator

Abstract

The photoluminescence quantum yield (PLQY) of copper indium sulfide (CIS) quantum dots (QDs) improves significantly after a shelling procedure as the shell materials, like zinc sulfide, mitigate surface defects and reduce nonradiative recombinations. However, it is widely observed that the PLQY reduces when QDs are cast as a solid film from their solution, and PL peak emission also red-shifts, which suggests a relaxation of the quantum confinement effect. This could be due to thin zinc sulfide shells. Unlike cadmiumbased QDs, reports on a thick zinc chalcogenide shell on CIS QDs are limited. Efforts to grow larger shells have been stymied by zinc diffusion toward the core, causing cation exchange and alloy formation. Thick zinc chalcogenide shell growth typically requires higher temperatures, a regime which would irreversibly degrade the PL of a CIS QD. Here, we develop a technique to grow thicker shells on CIS QDs to improve the quantum confinement effect between the QDs. With these thick shell CIS QDs, we demonstrate better emission as well as thermal and chemical stability. Finally, we demonstrate their application in a luminescent solar concentrator and showed that it has better light harvesting characteristics than its thin shell counterpart.

Review on Colloidal Quantum Dots Luminescent Solar Concentrators

“…Neo et al. synthesized thick ZnSe x S 1‐x shells around CuInS 2 QDs via a fast crystallization method to eliminate the degradation issue [156] . Zn, Se, and S precursors were synthesized with a rapid heating/cooling CuInS 2 synthesis strategy.…”

Soft luminescent solar concentrator film with organic dye and rubbery matrix

“…In Equation 7, n is the refractive index of the plate material. Because the refractive index of soda-lime glass, which is the substrate of the LSCs, has been reported by Vogt et al, [28] the reflection coefficient (r) of the LSC substrate can be calculated using Equation (7). The term e −ad in Equation (8) can be calculated using Equation (12), which shows that the absorption coefficient (a) of the plate can be obtained from the transmittance (T), thickness (d), and reflection coefficient (r).…”

“…[1][2][3][4][5] One of the most important issues has been the improvement of light collection efficiency with the development of high Stokes-shift luminescent materials in both organic and inorganic luminescent materials since the transporting ability of light has to be maintained on the large-area LSC. For high Stoke shift, quantum well has been designed through the core-shell structure of quantum dot in inorganic materials, [6,7] and the fluorescence resonance energy transfer system between donor and acceptor molecule has been proposed and developed inorganic materials. [8,9] This heterojunction structure of semiconductor materials has been suggested for highperformance LSC.…”

High Efficiency Luminescent Solar Concentrator based on Organo‐Metal Halide Perovskite Quantum Dots with Plasmon Enhancement

“…[ 1,7,11 ] The most commonly used fluorescent components include organic dyes and semiconductor quantum dots (QDs) such as CdSe/CdS, CdSe/ZnS, PbS, and Si. [ 1,2,5,6,12–16 ] The highest power conversion efficiency (PCE) to date is 7%, achieved in a dye‐based LSC when it is coupled to GaAs photovoltaic (PV) cells. [ 17 ] However, this same LSC, when coupled to Si PV cells, displayed a PCE of 2.9%.…”