scholarly journals Superlattice hole injection layers for UV LEDs grown on SiC

2020 ◽  
Vol 10 (9) ◽  
pp. 2171
Author(s):  
Christian J. Zollner ◽  
Abdullah S. Almogbel ◽  
Yifan Yao ◽  
Michael Wang ◽  
Michael Iza ◽  
...  
Keyword(s):  
Hole Injection ◽  
Uv Leds

scholarly journals 229 nm UV LEDs on aluminum nitride single crystal substrates using p-type silicon for increased hole injection

2018 ◽  
Vol 112 (8) ◽  
pp. 081101 ◽  
Author(s):  
Dong Liu ◽  
Sang June Cho ◽  
Jeongpil Park ◽  
Jung-Hun Seo ◽  
Rafael Dalmau ◽  
...  
Keyword(s):  
Aluminum Nitride ◽  
Single Crystal ◽  
Hole Injection ◽  
Type Silicon ◽  
P Type ◽  
Uv Leds

scholarly journals Reflective metal/semiconductor tunnel junctions for hole injection in AlGaN UV LEDs

2017 ◽  
Vol 111 (5) ◽  
pp. 051104 ◽  
Author(s):  
Yuewei Zhang ◽  
Sriram Krishnamoorthy ◽  
Fatih Akyol ◽  
Jared M. Johnson ◽  
Andrew A. Allerman ◽  
...  
Keyword(s):  
Tunnel Junctions ◽  
Hole Injection ◽  
Uv Leds

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.

Low Resistive and Low Absorptive Nitride-Based Tunnel junctions

2015 ◽  
Vol 1736 ◽  
Author(s):  
Daichi Minamikawa ◽  
Daiki Takasuka ◽  
Masataka Ino ◽  
Motoaki Iwaya ◽  
Tetsuya Takeuchi ◽  
...  
Keyword(s):  
Tunnel Junction ◽  
Reverse Bias ◽  
Tunnel Junctions ◽  
Voltage Drop ◽  
Hole Injection ◽  
Si Doping ◽  
Si Doped ◽  
Deep Uv ◽  
Uv Leds ◽  
Mg Doped

ABSTRACTWe have investigated two approaches for an alternative hole injection with a tunnel junction targeting deep UV-LEDs. One was an AlGaN-based tunnel junction. We fabricated the AlGaN-based tunnel junctions with various AlN mole fractions (0～0.2) grown on conventional blue-LEDs by MOVPE. A 7.5 nm heavily Mg-doped GaN/15 nm heavily Si-doped Al0.2Ga0.8N tunnel junction showed a large voltage drop, 5.31 V at 20 mA, under reverse bias. The other was a GaInN-based tunnel junction. We prepared Ga0.6In0.4N tunnel junctions with various thicknesses and Si doping levels grown on the blue LEDs by MOVPE. A 2 nm heavily Mg-doped Ga0.6In0.4N/3 nm heavily Si-doped GaN tunnel junction showed only 0.12 V drop at 20mA under reverse bias. Since an absorption of the thin GaInN tunnel junction was estimated to be less than 10 %, such a tunnel junction with small bandgap and thin layer thickness is a practical approach to obtain a low resistive and low absorptive hole injection in the deep UV-LEDs.

226 nm AlGaN/AlN UV LEDs using p-type Si for hole injection and UV reflection

2018 ◽  
Vol 113 (1) ◽  
pp. 011111 ◽  
Author(s):  
Dong Liu ◽  
Sang June Cho ◽  
Jeongpil Park ◽  
Jiarui Gong ◽  
Jung-Hun Seo ◽  
...  
Keyword(s):  
Hole Injection ◽  
P Type ◽  
Uv Leds ◽  
Uv Reflection

Effective performance improvement of organic thin film transistors with multi-layer modifications

2020 ◽  
Vol 91 (3) ◽  
pp. 30201
Author(s):  
Hang Yu ◽  
Jianlin Zhou ◽  
Yuanyuan Hao ◽  
Yao Ni
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Performance Enhancement ◽  
Organic Thin Film Transistors ◽  
Electrical Performance ◽  
Hole Injection ◽  
Organic Thin Film ◽  
Effective Performance ◽  
Significant Performance ◽  
P Type

Organic thin film transistors (OTFTs) based on dioctylbenzothienobenzothiophene (C8BTBT) and copper (Cu) electrodes were fabricated. For improving the electrical performance of the original devices, the different modifications were attempted to insert in three different positions including semiconductor/electrode interface, semiconductor bulk inside and semiconductor/insulator interface. In detail, 4,4′,4′′-tris[3-methylpheny(phenyl)amino] triphenylamine (m-MTDATA) was applied between C8BTBTand Cu electrodes as hole injection layer (HIL). Moreover, the fluorinated copper phthalo-cyanine (F16CuPc) was inserted in C8BTBT/SiO2 interface to form F16CuPc/C8BTBT heterojunction or C8BTBT bulk to form C8BTBT/F16CuPc/C8BTBT sandwich configuration. Our experiment shows that, the sandwich structured OTFTs have a significant performance enhancement when appropriate thickness modification is chosen, comparing with original C8BTBT devices. Then, even the low work function metal Cu was applied, a normal p-type operate-mode C8BTBT-OTFT with mobility as high as 2.56 cm2/Vs has been fabricated.

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.

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