scholarly journals Dopant-Tunable Ultrathin Transparent Conductive Oxides for Efficient Energy Conversion Devices

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Dae Yun Kang ◽  
Bo-Hyun Kim ◽  
Tae Ho Lee ◽  
Jae Won Shim ◽  
Sungmin Kim ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Indium Tin Oxide ◽  
Carrier Transport ◽  
Hole Injection ◽  
Visible Range ◽  
Transparent Conductive Oxides ◽  
Light Emitting ◽  
Efficient Energy ◽  
Uv Leds ◽  
Energy Conversion Devices

AbstractUltrathin film-based transparent conductive oxides (TCOs) with a broad work function (WF) tunability are highly demanded for efficient energy conversion devices. However, reducing the film thickness below 50 nm is limited due to rapidly increasing resistance; furthermore, introducing dopants into TCOs such as indium tin oxide (ITO) to reduce the resistance decreases the transparency due to a trade-off between the two quantities. Herein, we demonstrate dopant-tunable ultrathin (≤ 50 nm) TCOs fabricated via electric field-driven metal implantation (m-TCOs; m = Ni, Ag, and Cu) without compromising their innate electrical and optical properties. The m-TCOs exhibit a broad WF variation (0.97 eV), high transmittance in the UV to visible range (89–93% at 365 nm), and low sheet resistance (30–60 Ω cm−2). Experimental and theoretical analyses show that interstitial metal atoms mainly affect the change in the WF without substantial losses in optical transparency. The m-ITOs are employed as anode or cathode electrodes for organic light-emitting diodes (LEDs), inorganic UV LEDs, and organic photovoltaics for their universal use, leading to outstanding performances, even without hole injection layer for OLED through the WF-tailored Ni-ITO. These results verify the proposed m-TCOs enable effective carrier transport and light extraction beyond the limits of traditional TCOs.

Controlled Injection of Holes into ALQ3 Based Oleds by Means of An Oxidized Transport Layer

2001 ◽  
Vol 708 ◽  
Author(s):  
Mathew K. Mathai ◽  
Keith A. Higginson ◽  
Bing R. Hsieh ◽  
Fotios Papadimitrakopoulos
Keyword(s):  
Indium Tin Oxide ◽  
Oxidative Degradation ◽  
Transport Layer ◽  
Hole Injection ◽  
Carrier Injection ◽  
Salt Loading ◽  
Light Emitting ◽  
Hole Transporting ◽  
Intrinsic Degradation ◽  
Variable Conductivity

ABSTRACTIn this paper we report a method for tuning the extent of hole injection into the active light emitting tris- (8-hydroxyquinoline) aluminum (Alq3) layer in organic light emitting diodes (OLEDs). This is made possible by modifying the indium tin oxide (ITO) anode with an oxidized transport layer (OTL) comprising a hole transporting polycarbonate of N,N'-bis(3-hydroxymethyl)-N,N'-bis(phenyl) benzidine and diethylene glycol (PC-TPB-DEG) doped with varying concentrations of antimonium hexafluoride salt of N,N,N',N'-tetra-p-tolyl-4,4'-biphenyldiamine (TMTPD+ SbF6-). The conductivity of the OTL can be changed over three orders of magnitude depending on salt loading. The analysis of hole and electron current variations in these devices indicates that optimizing the conductivity of the OTL enables the modulation of hole injection into the Alq3 layer. The bipolar charge transport properties for OLEDs in which the interfacial carrier injection barriers have been minimized, are governed by the conductivities of the respective layers and in this case it is shown that the variable conductivity of the OTL does allow for better control of the same. Accordingly, varying the concentration of holes in the device indicates that beyond an optimum concentration of holes, further hole injection results in the formation of light quenching cationic species and the initiation of oxidative degradation processes in the Alq3 layer, thus accelerating the intrinsic degradation of these devices. The variable conductivity of the OTL can hence be used to minimize the occurrence of these processes.

Power-dependent photophysical pathways of upconversion in BaTiO3:Er3+

2021 ◽  
Author(s):  
Hyeongyu Bae ◽  
Eunsang Lee ◽  
Kang Taek Lee
Keyword(s):  
Energy Conversion ◽  
Light Emitting ◽  
Efficient Energy

Lanthanide incorporated perovskite is one of the most promising systems for efficient energy conversion or light-emitting materials in terms of upconversion (UC). The photophysical mechanism of UC in the lanthanide-doped...

Effect of ITO Carrier Concentration on the Performance of Organic Light-Emitting Diodes

1999 ◽  
Vol 598 ◽  
Author(s):  
Furong Zhu ◽  
Keran Zhang ◽  
C. H. A. Huan ◽  
A.T.S. Wee ◽  
Ewald Guenther ◽  
...  
Keyword(s):  
Carrier Concentration ◽  
Indium Tin Oxide ◽  
Film Deposition ◽  
Hole Injection ◽  
Maximum Efficiency ◽  
High Carrier Concentration ◽  
Band Bending ◽  
Light Emitting ◽  
Organic Light ◽  
High Carrier

ABSTRACTThe indium tin oxide (ITO) anodes for organic light emitting diode (OLED) were made from an oxidised target with In2O3 and SnO2 in a weight proportion of 9:1 using the RF magnetron sputtering method. The comparable ITO anodes with different carrier concentrations were prepared by varying the hydrogen partial pressure during film deposition. The current-luminance-voltage characteristics of the devices indicated that a high carrier concentration in ITO plays a role in improving OLED performance. A maximum efficiency of 3.8 cd/A was achieved when an ITO anode with a higher carrier concentration of 9×1020 cm−3 was used in a fluorene based OLED. This efficiency is about 1.5 times higher than that of an identical device made with an ITO anode having a lower carrier concentration of 5×1020 cm−3. The increase in electroluminescent efficie ncy reflects an enhanced hole-injection in the device. We consider that enhanced hole injection is due to the reduced band bending in ITO when it has a high carrier concentration

scholarly journals Yb:MoO3/Ag/MoO3 Multilayer Transparent Top Cathode for Top-Emitting Green Quantum Dot Light-Emitting Diodes

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 663
Author(s):  
Chun-Yu Lee ◽  
Yi-Min Chen ◽  
Yao-Zong Deng ◽  
Ya-Pei Kuo ◽  
Peng-Yu Chen ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Indium Tin Oxide ◽  
Light Emitting Diodes ◽  
Thin Metal ◽  
Visible Range ◽  
Driving Voltage ◽  
High Current Efficiency ◽  
Light Emitting ◽  
Indium Zinc Oxide ◽  
Average Transmittance

In this study, we report on the application of a dielectric/ultra-thin metal/dielectric (DMD) multilayer consisting of ytterbium (Yb)-doped molybdenum oxide (MoO3)/silver (Ag)/MoO3 stacked as the transparent cathode in top-emitting green quantum dot light-emitting diodes (QLED). By optimizing the Yb doping ratio, we have highly improved the electron injection ability from 0.01 to 0.35. In addition, the dielectric/ultra-thin metal/dielectric (DMD) cathode also shows a low sheet resistance of only 12.2 Ω/sq, which is superior to the resistance of the commercially-available indium tin oxide (ITO) electrode (~15 Ω/sq). The DMD multilayer exhibits a maximum transmittance of 75% and an average transmittance of 70% over the visible range of 400–700 nm. The optimized DMD-based G-QLED has a smaller current leakage at low driving voltage. The optimized DMD-based G-QLED enhances the current density than that of G-QLED with indium zinc oxide (IZO) as a cathode. The fabricated DMD-based G-QLED shows a low turn-on voltage of 2.2 V, a high current efficiency of 38 cd/A, and external quantum efficiency of 9.8. These findings support the fabricated DMD multilayer as a promising cathode for transparent top-emitting diodes.

scholarly journals Enhancement of hole injection using ozone treated Ag nanodots dispersed on indium tin oxide anode for organic light emitting diodes

2007 ◽  
Vol 90 (16) ◽  
pp. 163516 ◽  
Author(s):  
Jong-Min Moon ◽  
Jung-Hyeok Bae ◽  
Jin-A Jeong ◽  
Soon-Wook Jeong ◽  
No-Jin Park ◽  
...  
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Hole Injection ◽  
Light Emitting ◽  
Organic Light ◽  
Oxide Anode

Enhancing the hole injection ability of indium tin oxide viaammonium salts in polymer light-emitting diodes

2013 ◽  
Vol 1 (3) ◽  
pp. 531-535 ◽  
Author(s):  
Kai-Wei Tsai ◽  
Sung-Nien Hsieh ◽  
Tzung-Fang Guo ◽  
Yao-Jane Hsu ◽  
Alex K.-Y. Jen ◽  
...  
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Light Emitting Diodes ◽  
Hole Injection ◽  
Light Emitting ◽  
Polymer Light Emitting Diodes

scholarly journals Oxygen Plasma Surface Treatment onto ITO Surface for OLEDs Based on Europium Complex

2015 ◽  
Vol 10 (1) ◽  
pp. 7-12
Author(s):  
Gerson Santos ◽  
Marco R. Cavallari ◽  
Fernando J. Fonseca ◽  
Luiz Pereira
Keyword(s):  
Surface Treatment ◽  
Indium Tin Oxide ◽  
Oxygen Plasma ◽  
Transparent Electrode ◽  
Film Structure ◽  
Hole Injection ◽  
Light Emitting ◽  
Plasma Surface ◽  
Plasma Surface Treatment ◽  
Cie Chromaticity

In this work, Organic Light-Emitting Diodes (OLEDs) based on Europium (III) complex were studied, especially those with an oxygen plasma surface treatment onto indium tin oxide (ITO) transparent electrode. An OLED with the same thin-film structure but with untreated ITO was fabricated for comparison purposes. Current density-voltage characteristics for treated devices demonstrated an increase from 0.4 to 3.3 mA/cm² and a decrease of the turn-on voltage from 28 to 22 V. Additionally, improved hole injection through the transparent electrode impacted on optical response, as luminous efficiency increased from 26 to 44 mcd/A with the advantage of no significant disturb on the europium typical electroluminescence emission spectrum. Emission peak was observed at a wavelength of approximately 614 nm, which is defined by the transition associated with spectroscopic terms (5D0→7D2) and CIE chromaticity coordinates of (0.50;0.36).

Efficient and bright phosphorescent organic light-emitting diodes adopting MoO3/PEDOT:PSS as dual hole injection layers

2019 ◽  
Vol 33 (24) ◽  
pp. 1950284
Author(s):  
Nan Zhang ◽  
Yang Chen ◽  
Yan-Hui Wang
Keyword(s):  
Indium Tin Oxide ◽  
High Performance ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Acid Corrosion ◽  
Organic Light Emitting Diodes ◽  
Superior Performance ◽  
Hole Injection ◽  
Light Emitting ◽  
Organic Light

It has been demonstrated that high efficiency and brightness can be achieved in phosphorescent organic light-emitting diodes (PHOLEDs) by using molybdenum oxide (MoO3)/poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) as dual hole injection layers (HILs) on indium tin oxide (ITO) substrate. The dual HILs were simply fabricated by spin-coating PEDOT:PSS solution on a thin MoO3 layer deposited by vacuum thermal evaporation. This work reveals that PEDOT:PSS coating on MoO3 resulted in a smoother surface, simultaneously MoO3 lamella prevented acid corrosion of PEDOT:PSS on ITO. Meanwhile, with the insertion of PEDOT:PSS and MoO3 as HILs between anode and hole transporting layer (HTL), the energy barrier has been reduced and gave rise to effective hole injection. OLEDs with dual HILs resulted in the maximum current efficiency (CE) of 61.3 cd A[Formula: see text] and maximum luminance of 112200 cd cm[Formula: see text], which showed a superior performance compared to those devices with single HIL of PEDOT:PSS or MoO3. Our results proved the composition of PEDOT:PSS and MoO3 as HILs were beneficial for high performance OLEDs.

Sign in / Sign up

Export Citation Format

Share Document