Tuning Composite Nanomaterials through Energy Migration: From Luminescence Enhancement to Optoelectronic Device Application

Description

Lanthanide-doped inorganic crystals represent an important class of luminescent materials that have excelled in lighting, display, and lasering in the 20th century. These materials have a number of advantages including very high stability, low cost, and tunable emission colors. For example, conventional cathode ray tube (CRT) screens comprising Eu-doped YVO4 phosphors can perform for more than ten years without significant loss of brightness. However, lanthanide-based phosphors typically do not exhibit luminescence without intense excitations such as laser irradiation and electron bombardment. These phosphors are therefore unsuitable for most of today's applications in integrated devices including LEDs and photovoltaic cells. Herein, we proposed to develop a new generation of composite luminescent nanomaterials comprising lanthanide-doped nanocrystals conjugated with semiconductor quantum dots. We intend to use the quantum dots as antennae for collecting the excitations by electrical fields or solar light and for subsequently sensitizing the luminescence of lanthanide-doped nanocrystals through non-radiative energy transfer. Importantly, we have previously demonstrated that lanthanide-doped nanophosphors can exhibit tunable lights by doping different lanthanide ions at low dopant concentrations (< 5 mol %). Therefore, different-colored nanocomposites can be readily synthesized following a standard procedure. Once refined, we envision that these nanocomposites will open up the opportunity to constructing novel optoelectronic devices for a broad range of applications such as compact white LEDs and tunable lasers.