scholarly journals High-Performance Ultraviolet Light Detection Using Nano-Scale-Fin Isolation AlGaN/GaN Heterostructures with ZnO Nanorods

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 440 ◽  
Author(s):  
Fasihullah Khan ◽  
Waqar Khan ◽  
Sam-Dong Kim
Keyword(s):  
High Performance ◽  
Carrier Transport ◽  
Uv Light ◽  
Zno Nanorods ◽  
Response Speed ◽  
High Electron Mobility Transistor ◽  
Volume Effect ◽  
Light Illumination ◽  
High Electron ◽  
Nano Scale

Owing to their intrinsic wide bandgap properties ZnO and GaN materials are widely used for fabricating passive-type visible-blind ultraviolet (UV) photodetectors (PDs). However, most of these PDs have a very low spectral responsivity R, which is not sufficient for detecting very low-level UV signals. We demonstrate an active type UV PD with a ZnO nanorod (NR) structure for the floating gate of AlGaN/GaN high electron mobility transistor (HEMT), where the AlGaN/GaN epitaxial layers are isolated by the nano-scale fins (NFIs) of two different fin widths (70 and 80 nm). In the dark condition, oxygen adsorbed at the surface of the ZnO NRs generates negative gate potential. Upon UV light illumination, the negative charge on the ZnO NRs is reduced due to desorption of oxygen, and this reversible process controls the source-drain carrier transport property of HEMT based PDs. The NFI PDs of a 70 nm fin width show the highest R of a ~3.2 × 107 A/W at 340 nm wavelength among the solid-state UV PDs reported to date. We also compare the performances of NFI PDs with those of conventional mesa isolation (MI, 40 × 100 µm2). NFI devices show ~100 times enhanced R and on-off current ratio than those of MI devices. Due to the volume effect of the small active region, a much faster response speed (rise-up and fall-off times of 0.21 and 1.05 s) is also obtained from the NFI PDs with a 70 nm fin width upon the UV on-off transient.

scholarly journals Layered boron nitride enabling high-performance AlGaN/GaN high electron mobility transistor

2020 ◽  
Vol 829 ◽  
pp. 154542 ◽  
Author(s):  
Bing Ren ◽  
Meiyong Liao ◽  
Masatomo Sumiya ◽  
Jian Li ◽  
Lei Wang ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Electron Mobility ◽  
High Performance ◽  
High Electron Mobility Transistor ◽  
High Electron ◽  
High Electron Mobility

scholarly journals Synthesis of g-C3N4-Decorated ZnO Porous Hollow Microspheres for Room-Temperature Detection of CH4 under UV-Light Illumination

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1507 ◽  
Author(s):  
Min Xiao ◽  
Yanwei Li ◽  
Bo Zhang ◽  
Guang Sun ◽  
Zhanying Zhang
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
Uv Light ◽  
Response Speed ◽  
Hollow Microspheres ◽  
Oxide Semiconductor ◽  
Light Illumination ◽  
Long Term Stability ◽  
Temperature Detection ◽  
Good Repeatability

UV light-assisted gas sensors based on metal oxide semiconductor (MOS) have attracted much attention in detecting flammable and explosive gases at room temperature. In this paper, graphite-based carbon nitride (g-C3N4) nanosheets-decorated ZnO porous hollow microspheres (PHMSs) with the size about 3~5 μm in diameter were successfully synthesized by annealing the solvothermally-synthesized Zn5(CO3)2(OH)6 PHMSs together with g-C3N4. The synthesized samples were characterized by XRD, SEM, TEM, FT-IR and XPS. The results indicated that the prepared g-C3N4/ZnO PHMSs were constructed by numerous loosely stacked ZnO nanoparticles of 20~30 nm in diameter. Gas sensing tests indicated that under UV light (365~385 nm) illumination, the sensors fabricated with g-C3N4/ZnO HPMSs showed an enhanced response and faster response speed than the pure ZnO counterpart at room temperature. In addition, the g-C3N4/ZnO sensor also exhibited good repeatability and long-term stability for CH4 detection.

scholarly journals A New XOR Structure Based on Resonant-Tunneling High Electron Mobility Transistor

VLSI Design ◽  
2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
Mohammad Javad Sharifi ◽  
Davoud Bahrepour
Keyword(s):  
Electron Mobility ◽  
Resonant Tunneling ◽  
High Performance ◽  
High Electron Mobility Transistor ◽  
High Electron ◽  
Xor Gate ◽  
High Electron Mobility ◽  
Existing Structures ◽  
Input And Output ◽  
Exclusive Or

A new structure for an exclusive-OR (XOR) gate based on the resonant-tunneling high electron mobility transistor (RTHEMT) is introduced which comprises only an RTHEMT and two FETs. Calculations are done by utilizing a new subcircuit model for simulating the RTHEMT in the SPICE simulator. Details of the design, input, and output values and margins, delay of each transition, maximum operating frequency, static and dynamic power dissipations of the new structure are discussed and calculated and the performance is compared with other XOR gates which confirm that the presented structure has a high performance. Furthermore, to the best of authors' knowledge, it has the least component count in comparison to the existing structures.

Phosphorus-Doped p-Type ZnS Nanowires and their Photodetecting Applications Based on Device Construction

2016 ◽  
Vol 42 ◽  
pp. 65-72 ◽  
Author(s):  
Xi Wei Zhang ◽  
Dan Hu ◽  
Dan Meng ◽  
Zhen Jie Tang ◽  
Zhi Wang
Keyword(s):  
High Performance ◽  
Uv Light ◽  
Hole Concentration ◽  
Chemical Deposition ◽  
Core Shell ◽  
Light Illumination ◽  
Chemical Deposition Method ◽  
P Type ◽  
Phosphorus Doped ◽  
Type Conduction

Phosphorus-doped p-type ZnS NWs were synthesized by chemical deposition method. The as-synthesized NWs shows obvious p-type conduction with a hole concentration of 8.35 × 1017 cm-3. ZnS-Si core-shell nanoheterojunction was fabricated by depositing Si thin film on the surface of ZnS NWs through a sputtering method. The core-shell nanostructure exhibited excellent photoresponse to white light and UV light. Under UV light illumination, a high performance with a responsibility of ~ 0.14 × 103 AW-1, a gain of ~ 0.69 × 103 and a detectivity of ~ 1.2 × 1010 cmHz1/2W-1 were obtained based on the ZnS-Si core-shell nanoheterojunction. This new nanostructure is expected to play an important role in the next-generation optoelectronic devices.

AlGaN/GaN Structures Grown by HVPE: Growth and Characterization

2003 ◽  
Vol 764 ◽  
Author(s):  
M.A. Mastro ◽  
D.V. Tsvetkov ◽  
A.I. Pechnikov ◽  
V.A. Soukhoveev ◽  
G.H. Gainer ◽  
...  
Keyword(s):  
Mass Production ◽  
High Performance ◽  
High Electron Mobility Transistor ◽  
Hydride Vapor Phase Epitaxy ◽  
High Electron ◽  
High Electron Mobility ◽  
Light Emitting ◽  
Device Structures ◽  
Ultraviolet Light Emitting Diodes ◽  
Growth Technology

AbstractThis letter reports on multi-layer submicron epitaxial device structures grown by hydride vapor phase epitaxy (HVPE). This is the first demonstration of both high electron mobility transistor (HEMT) devices and ultraviolet light emitting diodes (LED) emitting in the wavelength range from 305 to 340 nm based on AlGaN/GaN and AlGaN/AlGaN heterostructures grown by HVPE. Two unique aspects of this technological approach are the growth of Al-containing epitaxial material by HVPE and use of HVPE to form submicron multi-layer epitaxial structures. The high performance of HVPE grown devices presented in this report demonstrates the significant potential that exists for HVPE growth technology for mass production of device epitaxial wafers.

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