scholarly journals 32 × 32 Pixelated High-Power Flip-Chip Blue Micro-LED-on-HFET Arrays for Submarine Optical Communication

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3045
Author(s):  
Tae Kyoung Kim ◽  
Abu Bashar Mohammad Hamidul Islam ◽  
Yu-Jung Cha ◽  
Joon Seop Kwak
Keyword(s):  
Optical Communication ◽  
High Power ◽  
Flip Chip ◽  
Light Emitting Diode ◽  
Light Output ◽  
Drain Current ◽  
High Electron Mobility Transistor ◽  
Multiple Quantum ◽  
High Electron ◽  
Led Arrays

This work proposes the use of integrated high-power InGaN/GaN multiple-quantum-well flip-chip blue micro light-emitting diode (μ-LED) arrays on an AlGaN/GaN-based heterojunction field-effect transistor (HFET), also known as a high electron mobility transistor (HEMT), for various applications: underwater wireless optical communication (UWOC) and smart lighting. Therefore, we demonstrate high-power μ-LED-on-HEMT arrays that consist of 32 × 32 pixelated μ-LED arrays and 32 × 32 pixelated HEMT arrays and that are interconnected by a solder bump bonding technique. Each pixel of the μ-LED arrays emits light in the HEMT on-state. The threshold voltage, the off-state leakage current, and the drain current of the HEMT arrays are −4.6 V, <~1.1 × 10−9 A at gate-to-source voltage (VGS) = −10 V, and 21 mA at VGS = 4 V, respectively. At 12 mA, the forward voltage and the light output power (LOP) of μ-LED arrays are ~4.05 V and ~3.5 mW, respectively. The LOP of the integrated μ-LED-on-HEMT arrays increases from 0 to ~4 mW as the VGS increases from −6 to 4 V at VDD = 10 V. Each pixel of the integrated μ-LEDs exhibits a modulated high LOP at a peak wavelength of ~450 nm, showing their potential as candidates for use in UWOC.

scholarly journals Perspectives on UVC LED: Its Progress and Application

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 196
Author(s):  
Tsung-Chi Hsu ◽  
Yu-Tsai Teng ◽  
Yen-Wei Yeh ◽  
Xiaotong Fan ◽  
Kuo-Hsiung Chu ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Flip Chip ◽  
Layer Structure ◽  
Light Emitting Diode ◽  
Internal Quantum Efficiency ◽  
Reverse Current ◽  
Light Extraction ◽  
Epitaxial Layers ◽  
High Electron ◽  
Recombination Rates

High-quality epitaxial layers are directly related to internal quantum efficiency. The methods used to design such epitaxial layers are reviewed in this article. The ultraviolet C (UVC) light-emitting diode (LED) epitaxial layer structure exhibits electron leakage; therefore, many research groups have proposed the design of blocking layers and carrier transportation to generate high electron–hole recombination rates. This also aids in increasing the internal quantum efficiency. The cap layer, p-GaN, exhibits high absorption in deep UV radiation; thus, a small thickness is usually chosen. Flip chip design is more popular for such devices in the UV band, and the main factors for consideration are light extraction and heat transportation. However, the choice of encapsulation materials is important, because unsuitable encapsulation materials will be degraded by ultraviolet light irradiation. A suitable package design can account for light extraction and heat transportation. Finally, an atomic layer deposition Al2O3 film has been proposed as a mesa passivation layer. It can provide a low reverse current leakage. Moreover, it can help increase the quantum efficiency, enhance the moisture resistance, and improve reliability. UVC LED applications can be used in sterilization, water purification, air purification, and medical and military fields.

Analytical Study of ZnO-based HEMT for Power Switching

2021 ◽  
Author(s):  
Pawan Kumar ◽  
Sumit Chaudhary ◽  
Md Arif Khan ◽  
Sanjay Kumar ◽  
Shaibal Mukherjee
Keyword(s):  
Ion Beam ◽  
Drain Current ◽  
Cost Effective ◽  
High Electron Mobility Transistor ◽  
Switching Frequency ◽  
Physical Parameters ◽  
High Electron ◽  
Ion Beam Sputtering ◽  
Power Switching ◽  
Group Iii

Abstract We investigate the power switching mechanism to evaluate the power loss ( P D ) and efficiency ( η ) in MgZnO/ZnO (MZO)-based power high electron mobility transistor (HEMT), and physical parameters responsible for P D in molecular beam epitaxy (MBE) and dual ion beam sputtering (DIBS) grown MZO HEMT and compare the performance with the group III-nitride HEMTs. This work extensively probes all physical parameters such as two-dimensional electron gas (2DEG) density, mobility, switching frequency, and device dimension to study their impact on power switching in MZO HEMT. Results suggest that the MBE and DIBS grown MZO HEMT with the gate width ( W G ) of ∼ 205 and ∼ 280 mm at drain current coefficient (k) of 11 and 15, respectively, will achieve 99.96 and 99.95% of η and 9.03 and 12.53 W of P D , respectively. Moreover, W G value for DIBS-grown MZO HEMT is observed to further reduce in the range of 112-168 mm by using a Y 2 O 3 spacer layer leading to the maximum η in the range of 99.98-99.97% and the minimum P D in the range of 5-7 W. This work is significant for the development of cost-effective HEMTs for power switching applications.

scholarly journals High-Power GaN-Based Vertical Light-Emitting Diodes on 4-Inch Silicon Substrate

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1178 ◽  
Author(s):  
Qiang Zhao ◽  
Jiahao Miao ◽  
Shengjun Zhou ◽  
Chengqun Gui ◽  
Bin Tang ◽  
...  
Keyword(s):  
High Power ◽  
Silicon Substrate ◽  
Flip Chip ◽  
Heat Dissipation ◽  
Light Emitting Diodes ◽  
Light Output ◽  
Current Spreading ◽  
Light Emitting ◽  
Fabry Perot ◽  
Lift Off

We demonstrate high-power GaN-based vertical light-emitting diodes (LEDs) (VLEDs) on a 4-inch silicon substrate and flip-chip LEDs on a sapphire substrate. The GaN-based VLEDs were transferred onto the silicon substrate by using the Au–In eutectic bonding technique in combination with the laser lift-off (LLO) process. The silicon substrate with high thermal conductivity can provide a satisfactory path for heat dissipation of VLEDs. The nitrogen polar n-GaN surface was textured by KOH solution, which not only improved light extract efficiency (LEE) but also broke down Fabry–Pérot interference in VLEDs. As a result, a near Lambertian emission pattern was obtained in a VLED. To improve current spreading, the ring-shaped n-electrode was uniformly distributed over the entire VLED. Our combined numerical and experimental results revealed that the VLED exhibited superior heat dissipation and current spreading performance over a flip-chip LED (FCLED). As a result, under 350 mA injection current, the forward voltage of the VLED was 0.36 V lower than that of the FCLED, while the light output power (LOP) of the VLED was 3.7% higher than that of the FCLED. The LOP of the FCLED saturated at 1280 mA, but the light output saturation did not appear in the VLED.

High-power monolithic AlGaN/GaN high electron mobility transistor switches

2009 ◽  
Vol 1 (4) ◽  
pp. 339-345 ◽  
Author(s):  
Vincenzo Alleva ◽  
Andrea Bettidi ◽  
Walter Ciccognani ◽  
Marco De Dominicis ◽  
Mauro Ferrari ◽  
...  
Keyword(s):  
Insertion Loss ◽  
High Power ◽  
Integrated Circuit ◽  
State Of The Art ◽  
High Electron Mobility Transistor ◽  
High Electron ◽  
Monolithic Microwave Integrated Circuit ◽  
X Band ◽  
Power Handling Capability ◽  
Better Than

This work presents the design, fabrication, and test of X-band and 2–18 GHz wideband high-power single pole double throw (SPDT) monolithic microwave integrated circuit (MMIC) switches in microstrip gallium nitride (GaN) technology. Such switches have demonstrated state-of-the-art performances and RF fabrication yields better than 65%. In particular, the X-band switch exhibits 1 dB insertion loss, better than 37 dB isolation, and a power handling capability better than 39 dBm at a 1 dB insertion loss compression point; the wideband switch shows an insertion loss lower than 2.2 dB, better than 25 dB isolation, and an insertion loss compression of 1 dB at an input drive higher than 38.5 dBm in the entire bandwidth.

High Power LED Integrated With Silicon-Based Thermoelectric Cooler Package

2007 ◽  
Author(s):  
Ming-Ji Dai ◽  
Chih-Kuang Yu ◽  
Chun Kai Liu ◽  
Sheng-Liang Kuo
Keyword(s):  
High Power ◽  
Flip Chip ◽  
Light Emitting Diode ◽  
Infrared Camera ◽  
Junction Temperature ◽  
Integrating Sphere ◽  
Thermoelectric Cooler ◽  
High Power Led ◽  
Silicon Based ◽  
Light Efficiency

A new thermal management application of silicon-based thermoelectric (TE) cooler integrated with high power light emitting diode (LED) is investigated in present study. The silicon-based TE cooler herein is fabricated by MEMS fabrication technology and flip-chip assembly process that is used for high power LED cooling. An electrical-thermal conversion method is used to estimate the junction temperature of LED. Moreover, the Integrating Sphere is also used to measure the light efficiency of LED. The thermal images photographed by infrared camera demonstrated the cooling function of the silicon-based TE devices. The results also show that high power LED integrated with silicon-based thermoelectric cooler package can effectively reduce the thermal resistance to zero. In addition, the light efficiency of the LED (1W) will increase under low TE cooler input power (0.55W), which is about 1.3 times of that without TE cooler packaging.

V-Band Flip-Chip Assembled Gain Block Using In$_{0.6}$Ga$_{0.4}$As Metamorphic High-Electron-Mobility Transistor Technology

2011 ◽  
Vol 4 (10) ◽  
pp. 104105 ◽  
Author(s):  
Che-Yang Chiang ◽  
Heng-Tung Hsu ◽  
Chin-Te Wang ◽  
Chien-I Kuo ◽  
Heng-Shou Hsu ◽  
...  
Keyword(s):  
Electron Mobility ◽  
Flip Chip ◽  
High Electron Mobility Transistor ◽  
High Electron ◽  
High Electron Mobility ◽  
V Band

scholarly journals Multi-Domain Modelling of LEDs for Supporting Virtual Prototyping of Luminaires

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1909 ◽  
Author(s):  
András Poppe ◽  
Gábor Farkas ◽  
Lajos Gaál ◽  
Gusztáv Hantos ◽  
János Hegedüs ◽  
...  
Keyword(s):  
Thermal Environment ◽  
Light Emitting Diode ◽  
Virtual Prototyping ◽  
Multiple Quantum Well ◽  
Light Output ◽  
Operating Conditions ◽  
Domain Model ◽  
Multiple Quantum ◽  
Seamless Integration ◽  
Output Characteristics

This paper presents our approaches to chip level multi-domain LED (light emitting diode) modelling, targeting luminaire design in the Industry 4.0 era, to support virtual prototyping of LED luminaires through luminaire level multi-domain simulations. The primary goal of such virtual prototypes is to predict the light output characteristics of LED luminaires under different operating conditions. The key component in such digital twins of a luminaire is an appropriate multi-domain model for packaged LED devices that captures the electrical, thermal, and light output characteristics and their mutual dependence simultaneously and consistently. We developed two such models with this goal in mind that are presented in detail in this paper. The first model is a semi analytical, quasi black-box model that can be implemented on the basis of the built-in diode models of spice-like circuit simulators and a few added controlled sources. Our second presented model is derived from the physics of the operation of today’s power LEDs realized with multiple quantum well heterojunction structures. Both models have been implemented in the form of visual basic macros as well as circuit models suitable for usual spice circuit simulators. The primary test bench for the two circuit models was an LTspice simulation environment. Then, to support the design of different demonstrator luminaires of the Delphi4LED project, a spreadsheet application was developed, which ensured seamless integration of the two models with additional models representing the LED chips’ thermal environment in a luminaire. The usability of our proposed models is demonstrated by real design case studies during which simulated light output characteristics (such as hot lumens) were confirmed by luminaire level physical tests.

High-power AlGaN∕GaN dual-gate high electron mobility transistor mixers on SiC substrates

2004 ◽  
Vol 40 (12) ◽  
pp. 775 ◽  
Author(s):  
K. Shiojima ◽  
T. Makimura ◽  
T. Kosugi ◽  
S. Sugitani ◽  
N. Shigekawa ◽  
...  
Keyword(s):  
High Power ◽  
Electron Mobility ◽  
High Electron Mobility Transistor ◽  
High Electron ◽  
High Electron Mobility ◽  
Dual Gate

Viscosity-dependent drain current noise of AlGaN/GaN high electron mobility transistor in polar liquids

2013 ◽  
Vol 114 (20) ◽  
pp. 204503 ◽  
Author(s):  
J. Y. Fang ◽  
G. Y. Lee ◽  
J. I. Chyi ◽  
C. P. Hsu ◽  
Y. W. Kang ◽  
...  
Keyword(s):  
Electron Mobility ◽  
Drain Current ◽  
High Electron Mobility Transistor ◽  
Current Noise ◽  
High Electron ◽  
Polar Liquids ◽  
High Electron Mobility
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