Formation of an indium tin oxide nanodot/Ag nanowire electrode as a current spreader for near ultraviolet AlGaN-based light-emitting diodes

Park, Jae-Seong; Kim, Jae Ho; Kim, Jun Yong; Kim, Dae Hyun; Na, Jin Young; Kim, Sun Kyung; Kang, Daesung; Seong, Tae Yeon

doi:10.1088/1361-6528/28/4/045205

Cited by 10 publications

(8 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As shown in Figure 6d, LEDs with the ITO-only and ITO NDsonly electrodes exhibited forward voltages (V f ) of 3.50 and 3.80 V at 20 mA, respectively, while LEDs with ITO NDs/Ag NW electrodes had higher V f than the LEDs with the ITO-only electrode. 78 The LEDs with the ITO NDs/Ag NWs electrodes produced higher output power than those with the ITO-only electrode (Figure 6e), although the latter gave higher transmittance and lower forward voltage. This better performance was explained by the enhanced current spreading and the improved light extraction, as confirmed by finite-difference time-domain (FDTD) simulations.…”

Section: Nanomaterial-based Transparent P-type Electrodes-recentlymentioning

confidence: 95%

“…ITO nanodots (NDs) were also combined with Ag NWs as a p-type electrode in NUV AlGaN-based LEDs to increase light output power. 78 The Ag NWs were 30 ± 5 nm in diameter and 25 ± 5 μm in length. The 10 nm-thick ITO-only electrode had a transmittance of 98% at 385 nm, while the values for ITO ND/AgNW electrodes gave 83-88%.…”

Section: Nanomaterial-based Transparent P-type Electrodes-recentlymentioning

confidence: 98%

“…65 However, the LEDs with few-layer GR had a high forward voltage larger than 10 V at 2 mA and were burnt out at high current injection. Thus, to improve the contact resistance and the stability of nanomaterialbased TCEs, various techniques, including interface engineering, [69][70][71][72][73][74][75][76][77][78] hybrid nanomaterial structures, [79][80][81][82][83] and chemical doping, [84][85][86][87] have been extensively studied.…”

Section: Nanomaterial-based Transparent P-type Electrodes-recentlymentioning

confidence: 99%

See 2 more Smart Citations

Review—Group III-Nitride-Based Ultraviolet Light-Emitting Diodes: Ways of Increasing External Quantum Efficiency

Park

Kim

Cho

et al. 2017

ECS J. Solid State Sci. Technol.

Self Cite

View full text Add to dashboard Cite

There is a rapidly growing demand for highly efficient ultraviolet (UV) light sources for a wide variety of applications. In particular, state-of-the-art AlGaN deep UV light-emitting diodes (DUV LEDs) exhibit inadequately low external quantum efficiencies (EQEs). The low efficiencies are attributed to the inherent material properties of high-Al-content AlGaN including strained epitaxial layers, low carrier concentrations, and strong transverse magnetic (TM)-polarized light emission. Extensive efforts have been made to tackle these challenging issues and technological developments have been achieved and enabled the fabrication of reasonable EQE LEDs. In this review, recent advances in the growth of high-quality AlGaN epitaxial layers, transparent and reflective ohmic contacts, and light extraction for AlGaN-based UV LEDs are reviewed. Al x Ga 1-x N-based ultraviolet light-emitting diodes (UV LEDs) are of technological importance because of their applications in numerous areas such as water purification, biological analysis, sensing, epoxy curing, high-density optical storage, white light illumination, UV adhesives, 3-dimensional (3D) printer and UV-coating.1,2 These applications are made possible because of their wide bandgap energy range in the UV spectrum, which spans from 6.2 eV (AlN) to 3.4 eV (GaN), namely, from UV-A (320-400 nm), UV-B (290-320 nm) to UV-C (200-290 nm).3-7 The external quantum efficiency (EQE) of Al x Ga 1-x N-based UV LEDs decreases rapidly as the molar fraction (x) of Al increases, namely, as the wavelength decreases, as illustrated in Figure 1. 8 Thus, a great deal of effort has been made in order to improve the EQE of UV LEDs. The effort notwithstanding, however, the EQE of AlGaN-based UV LEDs is still insufficiently low. The typical EQE of UV LEDs, specifically in the UV-C spectral range (100-280 nm), is less than 5% and decreases down to 10 -6 % for 210-nm AlN-based UV LEDs. 4 These low EQEs are associated with the intrinsic material properties of Al x Ga 1-x N.1,2 Figure 2 exhibits a schematic diagram of a typical AlGaN UV LED structure grown on a sapphire substrate. The structure consists of a Si-doped n-type AlGaN, an Al x Ga 1-x N/Al y Ga 1-y N multiple-quantum well (MQW) active region, an AlGaN-based electron-blocking layer (EBL), a Mg-doped p-type AlGaN, and a Mg-doped p-type GaN. Almost every layer in the structure poses different technical issues, which limit the efficiency of UV LEDs, as shown in Figure 2. First, increasing the Al content generally results in a poor crystallinity of AlGaN epilayers, causing a poor internal quantum efficiency (IQE). Second, both n-type and ptype doping efficiencies of AlGaN are difficult to increase because the ionization energies of acceptor (Mg) and donor (Si) dopants largely increase with increasing Al content. The low doping efficiency causes several technological problems: (i) a poor electrical efficiency (EE) attributable to high-resistance contacts on resistive n-type and p-type AlGaN; (ii) current crowding causing non-uniform current in...

show abstract

Section: Nanomaterial-based Transparent P-type Electrodes-recentlymentioning

confidence: 95%

Section: Nanomaterial-based Transparent P-type Electrodes-recentlymentioning

confidence: 98%

Section: Nanomaterial-based Transparent P-type Electrodes-recentlymentioning

confidence: 99%

See 1 more Smart Citation

Review—Group III-Nitride-Based Ultraviolet Light-Emitting Diodes: Ways of Increasing External Quantum Efficiency

Park

Kim

Cho

et al. 2017

ECS J. Solid State Sci. Technol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Therefore, it is necessary to find more suitable materials to applicate transparent electrode. Metal nanowires (NWs) such as silver NWs and carbon nanotubes have been studied as promising candidates for replacing ITO in optoelectronic devices [3][4][5][6][7][8][9][10][11][12][13][14]. Among them, Ag NWs are especially promising because of their high conductivity (σ Ag = 6.3 × 10 7 S m −1 ) compared to other metals commonly used as electrode materials for LEDs [15].…”

Section: Introductionmentioning

confidence: 99%

“…2021, 11, 7747 2 of 9 in next-generation TCEs in LEDs. However, many groups have only focused on replacing ITO-based TCEs with Ag-NW-based TCEs [3][4][5][6][7][8][9][10][11][12]. By contrast, to enhance the properties of Ag-NW-based TCEs, our group recently reported TCEs based on Ag NWs and nanoparticles (NPs) in which localized surface plasmons (LSPs) are excited; consequently, the internal quantum efficiency (IQE) is improved by dipoles of quantum well (QW) and SP coupling of Ag metal, and the light extraction efficiency (LEE) is improved by NPs working as a leakage mode and act as scattering centers [16].…”

Section: Introductionmentioning

confidence: 99%

Silver-Nanowire-Based Localized-Surface-Plasmon-Assisted Transparent Conducting Electrode for High-Efficiency Light-Emitting Diode

Kim

et al. 2021

Applied Sciences

View full text Add to dashboard Cite

Silver nanowire (Ag NWs) networks with high transparency and low resistivity are widely used as promising candidates for the replacement of indium tin oxide (ITO)-based transparent conducting oxides (TCOs) in light-emitting diodes (LEDs). However, LEDs with Ag NW electrodes are less efficient than those with ITO electrodes because of their low electrical properties, such as high contact resistance and strong absorption in the visible region. In this work, we tried to improve the efficiency of LEDs with transparent conducting electrodes of Ag NWs networks via localized surface plasmons (LSPs) by adopting silver nanoparticles. We studied the effect of the thickness of the p-GaN layer on surface plasmon coupling. When a 45 nm thick p-GaN layer was used, the internal quantum efficiency was improved by LSP coupling between a dipole of QW and Ag NW/NP, and the light extraction was improved because the NPs afforded a leakage mode and acted as scattering centers.

show abstract

ITO/Ag/AlN/Al2O3 multilayer electrodes with conductive channels: Application in ultraviolet light-emitting diodes

Lee

Son

et al. 2018

Journal of Alloys and Compounds

View full text Add to dashboard Cite

Formation of an indium tin oxide nanodot/Ag nanowire electrode as a current spreader for near ultraviolet AlGaN-based light-emitting diodes

Cited by 10 publications

References 22 publications

Review—Group III-Nitride-Based Ultraviolet Light-Emitting Diodes: Ways of Increasing External Quantum Efficiency

Review—Group III-Nitride-Based Ultraviolet Light-Emitting Diodes: Ways of Increasing External Quantum Efficiency

Silver-Nanowire-Based Localized-Surface-Plasmon-Assisted Transparent Conducting Electrode for High-Efficiency Light-Emitting Diode

ITO/Ag/AlN/Al2O3 multilayer electrodes with conductive channels: Application in ultraviolet light-emitting diodes

Contact Info

Product

Resources

About