Light management using CsPbBr₃colloidal quantum dots for luminescent solar concentrators

Area of Science:

• Materials Science
• Nanotechnology
• Photovoltaics

Background:

• Colloidal quantum dots (CQDs) offer tunable optical properties for advanced applications.
• Cesium lead bromide (CsPbBr₃) is a promising perovskite material for optoelectronic devices.
• Luminescent solar concentrators (LSCs) aim to enhance solar energy harvesting efficiency.

Purpose of the Study:

• To synthesize CsPbBr₃ colloidal quantum dots using the hot-injection method.
• To characterize the optical and photophysical properties of the synthesized CQDs.
• To fabricate and evaluate an LSC device utilizing CsPbBr₃ CQDs.

Main Methods:

• Hot-injection synthesis of spherical CsPbBr₃ CQDs (∼10.5 nm diameter).
• UV-vis absorption and photoluminescence spectroscopy for optical characterization.
• Photoluminescence quantum yield (PLQY) and time-resolved photoluminescence (TRPL) measurements.
• Fabrication of an LSC device with CQDs embedded in poly(methyl methacrylate) (PMMA).

Main Results:

• Synthesized CsPbBr₃ CQDs with a bandgap of ∼2.3682 eV and emission peak at 2.352 eV.
• Achieved a high absolute PLQY of 60 ± 1% in PMMA.
• Measured a photoluminescence decay time of 25.36 ns.
• Fabricated LSC demonstrated an external optical conversion efficiency of ∼5.4% under one sun illumination.

Conclusions:

• CsPbBr₃ CQDs possess favorable properties for LSC applications, including broad spectral absorption and high PLQY.
• The fabricated LSC exhibits high external optical conversion efficiency and good photostability, thermal stability, and long-term ambient stability.
• CsPbBr₃ CQDs show potential for superior performance compared to other materials in LSC devices.