scholarly journals Copper Indium Disulfide Quantum Dot Light Emitting Diodes for Display and Lighting Technologies

2019 ◽  
Vol 20 (3) ◽  
Author(s):  
Stefano Barba
Keyword(s):  
Reaction Time ◽  
Quantum Dot ◽  
Large Scale ◽  
Light Emitting Diodes ◽  
Device Fabrication ◽  
Device Structure ◽  
Light Emitting ◽  
High Performing ◽  
Copper Indium Disulfide ◽  
Copper Indium

While significant advances in the development of quantum dot light emitting diodes (QLEDs) have been reported, these devices are primarily based on cadmium chalcogenide quantum dot (QD) materials. Both environmental and health concerns arise due to the toxicity of cadmium and consequently, alternative less toxic QDs must be developed for large scale QLED applications such as display and solid state lighting technologies.  In this work, copper indium disulfide (CIS) was investigated as an alternative QD material for QLED applications. Through experimentation with material synthesis and device fabrication, this project aimed to develop high performing CIS QLEDs. Several synthetic approaches were experimented with and it was determined that the injection of shorter chain 1-octanethoil as sulfur precursor with extensive shell reaction time resulted in highly luminescent QDs.  Single color QLEDs were fabricated based on typical device structure, using highly luminescent synthesized CIS QDs as the emissive layer in multilayer devices. Varying the shell reaction time of QDs in order to vary shell thickness resulted in significant differences in device performance. Using thicker shell QDs, high performing devices were obtained with the best performing QLEDs displaying a high peak current efficiency of 14.7 cd/A and high external quantum efficiency of 5.2%.

scholarly journals Optimization of Quantum Dot Thin Films using Electrohydrodynamic Jet Spraying for Solution-Processed Quantum Dot Light-Emitting Diodes

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tuan Canh Nguyen ◽  
Thi Thu Thuy Can ◽  
Woon-Seop Choi
Keyword(s):  
Quantum Dot ◽  
High Performance ◽  
Large Scale ◽  
Light Emitting Diodes ◽  
Good Method ◽  
Large Area ◽  
Solution Processed ◽  
Light Emitting ◽  
Line Method ◽  
Straight Line

Abstract The electrohydrodynamic (EHD) jet spraying process is a good method for making quantum dot (QD) layers in light-emitting diodes (LEDs). However, controlling the morphology and large-scale fabrication of the QD layers are critical for realizing all-solution-processed QD-LEDs with high performance. Three spraying techniques were used with the EHD jet spraying technique: a big circular film method, a spiral-line method, and a straight-line method. These techniques were used to obtain QD films with good uniformity. The straight-line spray showed the most promise to obtain a uniform QD layer with large area, and QD-LEDs made with this method showed better performance with a low turn-on voltage of 3.0 V, a luminance of 7801 cd/m2, and a maximum current efficiency of 2.93 cd/A.

NOISE CHARACTERISTICS AND RELIABILITY OF LIGHT EMITTING DIODES BASED ON NITRIDES

2007 ◽  
Vol 07 (03) ◽  
pp. L367-L378 ◽  
Author(s):  
SANDRA PRALGAUSKAITĖ ◽  
VILIUS PALENSKIS ◽  
JONAS MATUKAS ◽  
JUOZAS PETRULIS ◽  
GENADIJUS KURILČIK
Keyword(s):  
Light Emitting Diodes ◽  
Forward Bias ◽  
Reverse Current ◽  
Correlation Factor ◽  
Device Fabrication ◽  
Electrical Noise ◽  
Device Structure ◽  
Light Emitting ◽  
Noise Characteristics ◽  
Terminal Voltage

Optical and electrical noises and correlation factor between optical and electrical fluctuations of nitride-based light emitting diodes (LEDs) have been investigated under forward bias. Their electrical, optical and noise characteristics were compared with ones of LEDs of other materials. LED noise characteristic changes during aging have been measured, too. It is found that optical and electrical noise spectra under forward bias for more reliable LEDs distinguish by lower l/f type fluctuations and Lorentzian type noise at higher frequencies. LEDs with intensive 1/f noise demonstrate shorter lifetime. It is shown that reason of LED degradation is related with defects presence in device structure. These defects can be formed during device fabrication or appear during operation. An analysis of LED current-voltage and electrical noise characteristics under forward and reverse bias has shown that LEDs with intensive 1/f electrical noise, large reverse current (low reverse breakdown voltage) and larger terminal voltage under forward bias distinguish by short lifetime.

Bright and Efficient Full-Color Colloidal Quantum Dot Light-Emitting Diodes Using an Inverted Device Structure

Nano Letters ◽  
2012 ◽  
Vol 12 (5) ◽  
pp. 2362-2366 ◽  
Author(s):  
Jeonghun Kwak ◽  
Wan Ki Bae ◽  
Donggu Lee ◽  
Insun Park ◽  
Jaehoon Lim ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Light Emitting Diodes ◽  
Device Structure ◽  
Light Emitting ◽  
Full Color ◽  
Colloidal Quantum Dot ◽  
Inverted Device ◽  
Inverted Device Structure

Interface dipole for remarkable efficiency enhancement in all-solution-processable transparent inverted quantum dot light-emitting diodes

2018 ◽  
Vol 6 (10) ◽  
pp. 2596-2603 ◽  
Author(s):  
Lixiang Chen ◽  
Min-Hsuan Lee ◽  
Yiwen Wang ◽  
Ying Suet Lau ◽  
Ali Asgher Syed ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Light Emitting Diodes ◽  
Efficiency Enhancement ◽  
Light Emitting ◽  
High Performing ◽  
Interface Dipole ◽  
Solution Processable

We report our efforts to develop high performing all-solution-processable transparent inverted QD-LEDs by interposing an interface dipole between the ZnO ETL and the quantum dot light-emitting layer.

Electroluminescent Quantum Dot Light-Emitting Diodes with ZnO and MoO3 Carrier Transport Layers

2013 ◽  
Vol 677 ◽  
pp. 98-102 ◽  
Author(s):  
Chun Yuan Huang ◽  
Ping Hua Tsai ◽  
Ying Chih Chen ◽  
Hsin Chieh Yu ◽  
Yan Kuin Su
Keyword(s):  
Quantum Dot ◽  
Indium Tin Oxide ◽  
Light Emitting Diodes ◽  
Sol Gel ◽  
Hole Transport ◽  
Transport Layer ◽  
Hole Injection ◽  
Electron Transport Layer ◽  
Device Structure ◽  
Light Emitting

In this article, the quantum dot (QD) light emitting diodes (QDLEDs) with ZnO electron transport layer (ETL) and MoO3hole transport layer (HTL) were demonstrated. The ZnO ETL was fabricated by sol-gel method. To achieve balanced electron and hole injection, hole transport materials including 4,4'-di(N-carbazolyl)biphenyl (CBP) and MoO3were also adapted. The device structure can be simply depicted as indium tin oxide (ITO)/ZnO/Cs2CO3/QD/CBP/MoO3/Au. It was found that the Cs2CO3played an important role to facilitate radiative recombination and reduce the leakage current due to the poor quality of sol-gel fabricated ZnO thin film. Via inserting an annealed Cs2CO3buffer layer with proper thickness, red-emitting QDLEDs with low luminance turn-on voltage of 4.1 V and luminance larger than 100 cd/m2could be obtained. With our demonstration, QDLEDs with ZnO ETL can be a promising device structure for realizing QDLED’s commerizing.

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