scholarly journals A Novel Approach for Room-Temperature Intersubband Transition in GaN HEMT for Terahertz Applications

2021 ◽  
Author(s):  
Rakesh Kaneriya ◽  
Gunjan Rastogi ◽  
Palash Basu ◽  
Rajesh Upadhyay ◽  
Apurba Bhattacharya

Terahertz (THz) technology has attracted tremendous attention recently due to its promising applications in various domains such as medical, biological, industrial imaging, broadband, safety, communication, radar, space science, and so on. Due to non-availability of powerful sources and highly sensitive and efficient detectors, the so-called THz gap remains largely unfilled. Despite seamless efforts from electronics and photonics technology researchers, the desired level of technology development to fill the THz gap still remains a challenge. GaN-based HEMT structures have been investigated as potential THz sources and detectors by a number of researchers. This chapter presents a very new and versatile mechanism for electrical tuning of intersubband transitions (ISBT) GaN high electron mobility transition (HEMT) devices. ISBT phenomena are usually demonstrated in photonic devices like a quantum cascade laser (QCL). Here we explore ISBT in an electronic GaN HEMT device. Conventional photonic devices like a QCL are operated at cryogenic temperature to minimize thermal effect. Tuning the conduction band through external gate bias is an advantage of an HEMT device for room temperature (RT) THz applications. This chapter demonstrates the theoretical and experimental novel ISBT phenomenon in GaN HEMT is for potential ambient applications in the THz range.

RSC Advances ◽  
2017 ◽  
Vol 7 (88) ◽  
pp. 55835-55838 ◽  
Author(s):  
Xiangzhen Ding ◽  
Bin Miao ◽  
Zhiqi Gu ◽  
Baojun Wu ◽  
Yimin Hu ◽  
...  

An extended gate-AlGaN/GaN high electron mobility transistor (EG-AlGaN/GaN HEMT) with a high sensitivity for bioassay has been developed.


RSC Advances ◽  
2019 ◽  
Vol 9 (27) ◽  
pp. 15341-15349 ◽  
Author(s):  
Zhiqi Gu ◽  
Jin Wang ◽  
Bin Miao ◽  
Lei Zhao ◽  
Xinsheng Liu ◽  
...  

We propose a highly efficient surface modification strategy on an AlGaN/GaN high electron mobility transistor, where ethanolamine was utilized to functionalize the surface of GaN and provided amphoteric amine groups for bioassay application.


Author(s):  
Lény Baczkowski ◽  
Franck Vouzelaud ◽  
Dominique Carisetti ◽  
Nicolas Sarazin ◽  
Jean-Claude Clément ◽  
...  

Abstract This paper shows a specific approach based on infrared (IR) thermography to face the challenging aspects of thermal measurement, mapping, and failure analysis on AlGaN/GaN high electron-mobility transistors (HEMTs) and MMICs. In the first part of this paper, IR thermography is used for the temperature measurement. Results are compared with 3D thermal simulations (ANSYS) to validate the thermal model of an 8x125pm AIGaN/GaN HEMT on SiC substrate. Measurements at different baseplate temperature are also performed to highlight the non-linearity of the thermal properties of materials. Then, correlations between the junction temperature and the life time are also discussed. In the second part, IR thermography is used for hot spot detection. The interest of the system for defect localization on AIGaN/GaN HEMT technology is presented through two case studies: a high temperature operating life test and a temperature humidity bias test.


2018 ◽  
Vol 21 (7) ◽  
pp. 462-467
Author(s):  
Babak Sadeghi

Aim and Objective: Ultrafine Ag/ZnO nanotetrapods (AZNTP) have been prepared successfully using silver (I)–bis (oxalato) zinc complex and 1, 3-diaminopropane (DAP) with a phase separation system, and have been injected into a diethyl/water solution. Materials and Methods: This crystal structure and lattice constant of the AZNTP obtained were investigated by means of a SEM, XRD, TEM and UV-vis spectrum. Results: The results of the present study demonstrated the growth and characterization AZNTP for humidity sensing and DAP plays a key role in the determination of particle morphology. AZNTP films with 23 nm in arm diameter have shown highly sensitive, quick response sensor material that works at room temperature.


Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4160
Author(s):  
Xiaobin Li ◽  
Hongbo Ma ◽  
Junhong Yi ◽  
Song Lu ◽  
Jianping Xu

Compared with conventional forward converters, active clamp forward (ACF) converters have many advantages, including lower voltage stress on the primary power devices, the ability to switch at zero voltage, reduced EMI and duty cycle operation above 50%. Thus, it has been the most popular solution for the low bus voltage applications, such as 48 V and 28 V. However, because of the poor performance of Si MOSFETs, the efficiency of active clamp forward converters is difficult to further improved. Focusing on the bus voltage of 28 V with 18~36 V voltage range application, the Gallium Nitride high electron-mobility transistors (GaN HEMT) with ultralow on-resistance, low parasitic capacitances, and no reverse recovery, is incorporated into active clamp forward converters for achieving higher efficiency and power density, in this paper. Meanwhile, the comparative analysis is performed for Si MOSFET and GaN HEMT. In order to demonstrate the feasibility and validity of the proposed solution and comparative analysis, two 18~36 V input, 120 W/12 V output, synchronous rectification prototype with different power devices are built and compared in the lab. The experimental results show the GaN version can achieve the efficiency of 95.45%, which is around 1% higher than its counterpart under the whole load condition and the same power density of 2.2 W/cm3.


Author(s):  
Jiayan Chu ◽  
Quan Wang ◽  
Lijuan Jiang ◽  
Chun Feng ◽  
Wei Li ◽  
...  
Keyword(s):  

2021 ◽  
Vol 10 (1) ◽  
pp. 330-369
Author(s):  
Norizan M. Nurazzi ◽  
Norli Abdullah ◽  
Siti Z. N. Demon ◽  
Norhana A. Halim ◽  
Ahmad F. M. Azmi ◽  
...  

Abstract Graphene is a single-atom-thick sheet of sp2 hybridized carbon atoms that are packed in a hexagonal honeycomb crystalline structure. This promising structure has endowed graphene with advantages in electrical, thermal, and mechanical properties such as room-temperature quantum Hall effect, long-range ballistic transport with around 10 times higher electron mobility than in Si and thermal conductivity in the order of 5,000 W/mK, and high electron mobility at room temperature (250,000 cm2/V s). Another promising characteristic of graphene is large surface area (2,630 m2/g) which has emerged so far with its utilization as novel electronic devices especially for ultrasensitive chemical sensor and reinforcement for the structural component applications. The application of graphene is challenged by concerns of synthesis techniques, and the modifications involved to improve the usability of graphene have attracted extensive attention. Therefore, in this review, the research progress conducted in the previous decades with graphene and its derivatives for chemical detection and the novelty in performance enhancement of the chemical sensor towards the specific gases and their mechanism have been reviewed. The challenges faced by the current graphene-based sensors along with some of the probable solutions and their future improvements are also being included.


Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3815
Author(s):  
Renyun Zhang ◽  
Magnus Hummelgård ◽  
Joel Ljunggren ◽  
Håkan Olin

Metal-semiconductor junctions and interfaces have been studied for many years due to their importance in applications such as semiconductor electronics and solar cells. However, semiconductor-metal networks are less studied because there is a lack of effective methods to fabricate such structures. Here, we report a novel Au–ZnO-based metal-semiconductor (M-S)n network in which ZnO nanowires were grown horizontally on gold particles and extended to reach the neighboring particles, forming an (M-S)n network. The (M-S)n network was further used as a gas sensor for sensing ethanol and acetone gases. The results show that the (M-S)n network is sensitive to ethanol (28.1 ppm) and acetone (22.3 ppm) gases and has the capacity to recognize the two gases based on differences in the saturation time. This study provides a method for producing a new type of metal-semiconductor network structure and demonstrates its application in gas sensing.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saurabh Dixit ◽  
Nihar Ranjan Sahoo ◽  
Abhishek Mall ◽  
Anshuman Kumar

AbstractMid-infrared (IR) spectral region is of immense importance for astronomy, medical diagnosis, security and imaging due to the existence of the vibrational modes of many important molecules in this spectral range. Therefore, there is a particular interest in miniaturization and integration of IR optical components. To this end, 2D van der Waals (vdW) crystals have shown great potential owing to their ease of integration with other optoelectronic platforms and room temperature operation. Recently, 2D vdW crystals of $$\alpha$$ α -$$\hbox {MoO}_{3}$$ MoO 3 and $$\alpha$$ α -$$\hbox {V}_2 \hbox {O}_5$$ V 2 O 5 have been shown to possess the unique phenomenon of natural in-plane biaxial hyperbolicity in the mid-infrared frequency regime at room temperature. Here, we report a unique application of this in-plane hyperbolicity for designing highly efficient, lithography free and extremely subwavelength mid-IR photonic devices for polarization engineering. In particular, we show the possibility of a significant reduction in the device footprint while maintaining an enormous extinction ratio from $$\alpha$$ α -$$\hbox {MoO}_{3}$$ MoO 3 and $$\alpha$$ α -$$\hbox {V}_2$$ V 2 $$\hbox {O}_5$$ O 5 based mid-IR polarizers. Furthermore, we investigate the application of sub-wavelength thin films of these vdW crystals towards engineering the polarization state of incident mid-IR light via precise control of polarization rotation, ellipticity and relative phase. We explain our results using natural in-plane hyperbolic anisotropy of $$\alpha$$ α -$$\hbox {MoO}_{3}$$ MoO 3 and $$\alpha$$ α -$$\hbox {V}_2$$ V 2 $$\hbox {O}_5$$ O 5 via both analytical and full-wave electromagnetic simulations. This work provides a lithography free alternative for miniaturized mid-infrared photonic devices using the hyperbolic anisotropy of $$\alpha$$ α -$$\hbox {MoO}_{3}$$ MoO 3 and $$\alpha$$ α -$$\hbox {V}_2$$ V 2 $$\hbox {O}_5$$ O 5 .


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