Recent Progress in Quantum Dot Based White Light-Emitting Devices

Abstract

Colloidal semiconductor quantum dots (QDs) have been widely employed as components of white light-emitting diodes (WLEDs) due to their excellent optical properties (highly saturated emission color, high luminescence quantum yield) as well as thermal and chemical stability. Much effort has been devoted to realize efficient QD-based WLEDs, including the synthesis of superior luminescent nanomaterials with excellent stabilities, and the design of advanced devices structures. In this paper, after introducing photometric parameters of the contemporary QD-based WLEDs, we highlight the recent progress in these devices grouped according to three main mechanisms for white light generation: optical excitation, direct charge carrier injection, and Förster resonance energy transfer. The methods to generate white light, the design of QD emitters and QD-based devices, as well as their fabrication techniques are considered, and the key scientific and technological challenges in the QD-based WLEDs are highlighted. Novel light-emitting materials for WLEDs such as carbon-based nanoparticles are also considered.

Enhanced bandwidth of white light communication using nanomaterial phosphors

“…Thus, only a few megahertz (MHz) was realized for these conventional phosphor-based LEDs. Therefore, the nanomaterials with short relaxation time and high quantum yield (QY) have attracted extensive attention [24, 25]. …”

Metal halide perovskite nanocrystals and their applications in optoelectronic devices

“…For the electrically driven LEDs, they generally have a sandwich structure containing anode, hole transport layer (HTL), emitting layer (EML), electron transport layer (ETL), and cathode (Figure ). When a voltage is applied to the device, the hole and electron are injected from the anode and cathode and go through the HTL and ETL into the EML, where they form excitons and subsequently take place efficient radiative recombination to emit photons . Table summarizes the recent application of perovskite NCs in LEDs.…”

High Performance Wide Angle DBR Design for Optoelectronic Devices

“…III-nitride solid-state light emitters are attracting increasing attentions due to their wide applications ranging from light communication [1], high resolution display [2,3], energy harvest [4] and lasers [5,6]. For instance, the conventional approach is to mainly use InGaN/GaN-based blue light emitting diodes with color conversion phosphor materials, such as Y3Al5O12:Ge 3+ (YAG), to generate artificial white light [7,8]. Despite many works have been devoted to the development of white LED during the past decade, current GaN-based white LEDs are still mainly grown on sapphire substrate due to the consideration of lattice matching and coefficient of thermal expansion in the growth process [9,10].…”