Unconventional energy transfer from narrow to broad luminescent wide band gap materials

¹ Materials Research Centre, Indian Institute of Science - Bangalore 560-012, India
² International Center for Materials Nanoarchitectonics, National Institute for Materials Science Tsukuba, Ibaraki 305-0044, Japan

^(a) nanda@iisc.ac.in

Received: 29 January 2019
Accepted: 5 July 2019

Abstract

Here, we demonstrate an unconventional energy transfer with narrow band gap CdTe/PbS quantum dots as donors and broad luminescent wide-band-gap oxide materials as acceptors. As a result, the luminescence of wide band gap materials increases and the enhancement factor follows a linear process for photon conversion as in the case of Förster resonance energy transfer. In addition, the strong anti-reflection effect enabling efficient light harvesting, broad spectral overlapping and strong coupling between quantum dots and oxides are the key processes for the unconventional energy transfer. An enhancement of around ∼5500% is observed for GeO₂/PbS quantum dots which is higher than that reported for the conventional energy transfer process. The findings demonstrate unconventional energy transfer which enables a greater understanding and rational engineering of light harvesting devices and quantum light sources.