Extended Gate Field Effect Transistor Using GaN/Si Hybrids Nanostructures for pH Sensor

NANO ◽  
2017 ◽  
Vol 12 (09) ◽  
pp. 1750114 ◽  
Author(s):  
Manchen Zhang ◽  
Ruzhi Wang ◽  
Zhen Shen ◽  
Yuhang Ji

The pH sensor of an extended gate field effect transistor (EGFET) with gallium nitride/silicon hybrid nanostructure is fabricated and analyzed. Si nanowires (NWs) are fabricated via the Ag-assisted electroless etching technique and are then covered by GaN NWs through plasma-enhanced chemical vapor deposition (PECVD). The GaN nanostructure is synthesized by introducing gallium oxide (Ga2O3) and nitrogen (N2) for the growth of NWs. The GaN nanowires supply a larger surface area than that of the pristine Si NWs, where there is a better sensitivity for pH sensor. The GaN/Silicon hybrid sensors exhibit a sensitivity higher (50.4[Formula: see text]mV/pH) than that of pristine Si NWs sensors (41.2[Formula: see text]mV/pH). This GaN/Si hybrid pH sensor prepared by simple and low-cost method may be potentially applied for cheap biosensor devices.

2000 ◽  
Vol 639 ◽  
Author(s):  
Seikoh Yoshida ◽  
Hirotatsu Ishii

ABSTRACTA high-power metal semiconductor field-effect transistor (MESFET) for operating at a very large-current using GaN is reported for the first time. GaN was grown by metalorganic chemical vapor deposition (MOCVD). Sapphire substrates were used for GaN growth. A GaN MESFET with a large size was fabricated. Multi-finger gates were used for large-current operation. The total gate width was 8 cm and the gate length was 2 νm. The electrode materials of the source and the drain were Al/Ti/Au and the schottky electrodes were Pt/Au. The gate, source, and drain were isolated using SiO2. An FET structure was fabricated using a dry-etching technique. Multi-electrode structures were also fabricated using SiO2 for isolating the source, drain, and gate electrodes, respectively. The FET was operated at a current of over 5 A. The breakdown voltage was over 500 V. The transconductance (gm) was about 12 mS/mm. The pinch-off voltage was about -8 V. We confirmed that this GaN MESFET can also be operated at a current of 10 A.


2021 ◽  
pp. 100102
Author(s):  
Prashant Sharma ◽  
Rini Singh ◽  
Rishi Sharma ◽  
Ravindra Mukhiya ◽  
Kamlendra Awasthi ◽  
...  

2021 ◽  
Author(s):  
Shaiful Bakhtiar Hashim ◽  
Zurita Zulkifli ◽  
Sukreen Hana Herman

Abstract A SPICE model for extended-gate field-effect transistor (EGFET) based pH sensor was developed using standard discrete components. Capacitors and resistors were used to represent the sensing and reference electrodes in the EGFET sensor system and the values of the discrete component were varied to see the output of the transistor. These variations were done to emulate the EGFET sensor output in different pH values. It was found that the experimental transfer and output characteristics of the EGFET were very similar to those from the SPICE simulation. Other than that, the changes of value components in the equivalent circuit did not affect the transfer and output characteristics graph, but the capacitor value produced significant output variation in the simulation. This can be related to the modification on the equivalent circuit was done with additional voltage, VSB (source to bulk) to produce the different VT values at different pH.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Xin Li ◽  
Junjie Shi ◽  
Junchao Pang ◽  
Weihua Liu ◽  
Hongzhong Liu ◽  
...  

Graphene channel liquid container field effect transistor pH sensor with interdigital microtrench for liquid ion testing is presented. Growth morphology and pH sensing property of continuous few-layer graphene (FLG) and quasi-continuous monolayer graphene (MG) channels are compared. The experiment results show that the source-to-drain current of the graphene channel FET has a significant and fast response after adsorption of the measured molecule and ion at the room temperature; at the same time, the FLG response time is less than 4 s. The resolution of MG (0.01) on pH value is one order of magnitude higher than that of FLG (0.1). The reason is that with fewer defects, the MG is more likely to adsorb measured molecule and ion, and the molecules and ions can make the transport property change. The output sensitivities of MG are from 34.5% to 57.4% when the pH value is between 7 and 8, while sensitivity of FLG is 4.75% when thepH=7. The sensor fabrication combines traditional silicon technique and flexible electronic technology and provides an easy way to develop graphene-based electrolyte gas sensor or even biological sensors.


Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1753 ◽  
Author(s):  
Nikita Nekrasov ◽  
Dmitry Kireev ◽  
Nejra Omerović ◽  
Aleksei Emelianov ◽  
Ivan Bobrinetskiy

In this work, we report a novel method of maskless doping of a graphene channel in a field-effect transistor configuration by local inkjet printing of organic semiconducting molecules. The graphene-based transistor was fabricated via large-scale technology, allowing for upscaling electronic device fabrication and lowering the device’s cost. The altering of the functionalization of graphene was performed through local inkjet printing of N,N′-Dihexyl-3,4,9,10-perylenedicarboximide (PDI-C6) semiconducting molecules’ ink. We demonstrated the high resolution (about 50 µm) and accurate printing of organic ink on bare chemical vapor deposited (CVD) graphene. PDI-C6 forms nanocrystals onto the graphene’s surface and transfers charges via π–π stacking to graphene. While the doping from organic molecules was compensated by oxygen molecules under normal conditions, we demonstrated the photoinduced current generation at the PDI-C6/graphene junction with ambient light, a 470 nm diode, and 532 nm laser sources. The local (in the scale of 1 µm) photoresponse of 0.5 A/W was demonstrated at a low laser power density. The methods we developed open the way for local functionalization of an on-chip array of graphene by inkjet printing of different semiconducting organic molecules for photonics and electronics.


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