Highly Efficient Green‐Light‐Emitting Diodes Based on CdSe@ZnS Quantum Dots with a Chemical‐Composition Gradient

Abstract

Highly efficient green‐light‐emitting diodes (LEDs) based on CdSe@ZnS quantum dots (QDs) with a chemical‐composition gradient are demonstrated. Through the moderate control of QD coverage in multilayered devices, excellent device performance has been achieved. The color‐saturated green‐light emission (see figure for Commission Internationale de l'Eclairage (CIE) co‐ordinates) is mainly from the QD layers (more than 99% of total emission).

Implementation of graphene multilayer electrodes in quantum dot light-emitting devices

“…Thereby, PEDOT:PSS is acting as a hole-injection layer and poly-TPD as a holetransporting layer. It is also known that poly-TDP acts as an electron-blocking layer because of its wide band gap and the position of the valence and the conduction band edge [36]. Spin-coated QD layer acts as an active lightemitting layer, contacted by Al cathode (Fig.…”

Characterization of Quantum Dot/Conducting Polymer Hybrid Films and Their Application to Light‐Emitting Diodes

“…The highest external quantum efficiency (EQE) obtained with reproducibility is 1.5% based on 2.5 wt% QD content in the hybrid emissive film and the best efficiency data is 2.2%, as shown in Figure S6, outperforming the best QLEDs (among green QLEDs pre- viously reported) [14] in the range of practical brightness (100-1000 cd m…”

“…1 nm in length), QDs are typically dispersed in organic solvents such as toluene or chloroform, which are also good solvents for typical conjugated organic molecules or polymers and, thus, organic underlying layers in multilayer LED devices can be easily deteriorated during the QD deposition step. Previously, several approaches have been taken in order to prevent such possible damage to organic underlayers during the QD emission layer deposition: processing with a mixed solution of QD and organic matrix material, [8][9][10][11][12] the introduction of robust matrix layers (i.e., a cross-linkable or robust conjugated polymer [13][14][15] or metal oxide inorganic layer [16,17] ), or pattern transfer techniques (i.e. micro-contact printing of QDs [19] ).…”

CdSe/ZnS Colloidal Quantum Dots with Alloyed Core/Shell Interfaces: A Photoluminescence Dynamics Study

“…[5,6] with only marginal modifications. In 20 mL of 1-octadecene a 0.2 mmol of cadmium oxide, 2 mmol of zinc acetate and 5.5 ml of oleic acid (OA) were dispersed.…”