Hua Muchuan, Decca Ricardo S
Department of Physics, Indiana University Indianapolis, 402 N. Blackford St., BLDG LD154, Indianapolis, IN, 46202, USA.
Center for Nanoscale Materials, Argonne National Laboratory, 9700S Cass Avenue, Lemont, IL, 60439, USA.
Sci Rep. 2025 Apr 17;15(1):13286. doi: 10.1038/s41598-025-97958-5.
Critical progress in perfecting semiconducting quantum dots' photoluminescence quantum yield has been made in the past few years. The production of quantum dots with nearly unitary quantum yield has significantly expanded their possible applications, as it is the case of optical refrigeration. We report for the first time optical refrigeration achieved in cadmium selenide/cadmium sulfide (core/shell) structure nanocrystals. Experiments were carried out in colloidal quantum dots suspension, where the excitonic non-radiative decay paths of the quantum dots are effectively suppressed by applying sub-band excitation, eliminating the possible states for energy down-conversion. The cooling effect comes from the significant energy up-conversion observed in the photoluminescence spectra of the samples under sub-band excitation. These results highlight the possibility of realizing temperature control on semiconducting quantum dots through optical approaches, which could provide power cooling mechanism for nano devices and cryogenic systems.
在过去几年里，半导体量子点的光致发光量子产率的完善取得了关键进展。具有近乎单位量子产率的量子点的产生显著扩展了它们的可能应用，光学制冷就是这样的情况。我们首次报道了在硒化镉/硫化镉（核/壳）结构纳米晶体中实现的光学制冷。实验是在胶体量子点悬浮液中进行的，通过应用子带激发有效地抑制了量子点的激子非辐射衰变路径，消除了能量向下转换的可能状态。冷却效应来自于在子带激发下样品的光致发光光谱中观察到的显著的能量向上转换。这些结果突出了通过光学方法实现对半导体量子点温度控制的可能性，这可为纳米器件和低温系统提供功率冷却机制。
