Plasmon-induced fluorescence enhancement of near-infrared colloidal quantum dots for highly transparent building-integrated photovoltaics

Abstract

Due to their unique optical properties, hybrid nanostructures (NSs) composed of localized surface plasmon resonance (LSPR) noble metal nanoparticles (NPs) and inorganic quantum dots (QDs) can achieve enhanced photoluminescence (PL). However, high costs and low reserves of precious metals greatly limit their development into practical applications. It is still challenging to achieve LSPR-induced enhancement in PL emission of QDs in the second near-infrared (NIR) window (900-1700 nm) for practical use, as the radiative emission rate decreases. Herein we report the synthesis of noble-metal-free Cu_2-xSe@SiO₂@CuInSe_2-xS_x/ZnS core/shell/shell hybrid NSs (C@S@S for short) in the NIR region (PL emission centered at ~917 nm). These NSs exhibit absolute PL quantum yield (QY) of ~45% (E_ex=520 nm) and PL enhancement factor (EF) of 4.24 compared to the original CuInSe_2-xS_x/ZnS QDs. A fundamental understanding of the LSPR-enhancement mechanism in PL emission and the carrier dynamics in this NIR hybrid system has been proposed and demonstrated based on theoretical simulations and transient absorption measurements. As a proof of concept, the hybrid NSs are used to fabricate a highly transparent (visible light transmission of 89.1%) building-integrated photovoltaic (BIPV) system based on luminescent solar concentrator (LSC, dimensions of 6×6×0.3 cm³) and Si PVs, which exhibits an enhanced power conversion efficiency (PCE, 0.23%) and photostability with respect to those of sole QDs-based LSC-PV systems. This approach provides a feasible technological pathway to address the challenge of improving the PL performance of NIR QDs and opens up other opportunities in QD-based emerging optoelectronic technologies.