Net energy up-conversion processes in CdSe/CdS (core/shell) quantum dots, a possible pathway to towards optical cooling

TL;DR

This paper explores the potential of CdSe/CdS core/shell quantum dots for optical cooling by demonstrating significant energy up-conversion photoluminescence and developing a semi-empirical model that predicts net cooling effects.

Contribution

It presents experimental evidence of energy up-conversion in CdSe/CdS quantum dots and introduces a semi-empirical model to predict optical refrigeration capabilities.

Findings

Significant energy up-conversion photoluminescence observed

Model shows good agreement with experimental data

Potential for optical refrigeration demonstrated

Abstract

The investigation of the possibility of optical refrigeration (OR) on zinc-blende cadmium selenide/cadmium sulfide (CdSe/CdS) core/shell structure quantum dots (QDs) has been carried out. Quality samples were synthesized in our lab, and significant energy up-conversion photoluminescence (UCPL) was observed in these samples, showing the potential of generating net cooling effects. To better understand and predict the UCPL characteristics of the QDs, a semi-empirical model has been developed, showing good agreement with our experimental results. The model takes into account the corresponding quantum yield and cooling efficiency, predicting the possibility of realizing optical refrigeration on a CdSe QDs system.