  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.

Materials Science;Mesoscale and Nanoscale Physics;Chemical Physics;Optics