Resonance energy transfer in electrostatically assembled donor-acceptor system based on blue-emitting InP quantum dots

Abstract

Demonstration of light harvesting studies with blue-emitting quantum dots (QDs) is important to expand the scope of QDs in various optoelectronic applications including display, photocatalysis, energy and electron transfer processes, sensing, etc. Here, we report a light induced Förster resonance energy transfer (FRET) process in an all-QD based nanohybrid system containing pure-blue emitting indium phosphide (InP) QDs. A precise control over the kinetics of nucleation and growth processes resulted in the formation of environmentally friendly blue and green emitting InP QDs. The surfaces of the QDs were functionalized with oppositely charged ligands to form an electrostatically assembled donor-acceptor system based on blue and green emitting InP QDs. A large spectral overlap integral and the close proximity between the QDs in the electrostatically assembled donor-acceptor system led to an efficient FRET process (∼65%) from blue-emitting InP QDs to green-emitting InP QDs in water. Systematic steady-state and time-resolved spectroscopic studies revealed the involvement of both static as well as dynamic components in the photoluminescence quenching process. Control experiments conclusively prove the necessity of appropriately functionalized QDs and electrostatic attraction for achieving an efficient FRET process. In short, our work proves the ability of blue-emitting InP QDs to participate in an efficient FRET process, which can accelerate the development of all-QD based light harvesting systems for various optoelectronic applications.