Temperature-tuning of near-infrared monodisperse quantum dot solids at 1.5 um for controllable Forster energy transfer

TL;DR

This study investigates temperature-dependent Forster energy transfer in monodisperse lead sulphide quantum dots near 1.5 um, demonstrating controllable transfer efficiency and rates through cryogenic and room temperature tuning.

Contribution

First cryogenic time-resolved observations of Forster energy transfer in large lead sulphide quantum dots at near-infrared wavelengths, with temperature tuning for controllable transfer efficiency.

Findings

Achieved 94% energy transfer efficiency at optimal temperature.

Observed transfer rates of 30-50 ns^{-1} across temperature range.

Transfer rates align with theoretical models.

Abstract

We present the first time-resolved cryogenic observations of Forster energy transfer in large, monodisperse lead sulphide quantum dots with ground state transitions near 1.5 um (0.83 eV), in environments from 160 K to room temperature. The observed temperature-dependent dipole-dipole transfer rate occurs in the range of (30-50 ns)^(-1), measured with our confocal single-photon counting setup at 1.5 um wavelengths. By temperature-tuning the dots, 94% efficiency of resonant energy transfer can be achieved for donor dots. The resonant transfer rates match well with proposed theoretical models.