Investigation of steady-state and time-dependent luminescence properties of colloidal InGaP quantum dots

TL;DR

This study characterizes the steady-state and time-dependent luminescence properties of InGaP/ZnS colloidal quantum dots, highlighting their potential as non-toxic alternatives for biological imaging and sensing.

Contribution

It provides detailed luminescence data and demonstrates energy transfer effects, establishing InGaP quantum dots as promising non-toxic substitutes for traditional quantum dots.

Findings

Emission maximum at 650 nm with 85 nm FWHM

Bi-exponential decay with lifetimes of 47 ns and 142 ns

Luminescence quenching observed due to energy transfer

Abstract

Quantum dots play a promising role in the development of novel optical and biosensing devices. In this study, we investigated steady-state and time-dependent luminescence properties of InGaP/ZnS core/shell colloidal quantum dots in a solution phase at room temperature. The steady state experiments exhibited an emission maximum at 650 nm with full width at half maximum of ~ 85 nm, and strong first-excitonic absorption peak at 600 nm. The time-resolved luminescence measurements depicted a bi-exponential decay profile with lifetimes of {\tau}1\sim 47 ns and {\tau} 2\sim 142 ns at the emission maximum. Additionally, luminescence quenching and lifetime reduction due to resonance energy transfer between the quantum dot and an absorber are demonstrated. Our results support the plausibility of using these InGaP quantum dots as an effective alternative to highly toxic conventional Cd or Pb based colloidal quantum dots for biological applications.