Photoconductivity Dependence on the Background Oxygen Pressure in Nanostructured ZnO UV Sensor

2009 ◽  
Vol 1178 ◽  
Author(s):  
Nilima V Hullavarad ◽  
Shiva S Hullavarad
Keyword(s):  
Electronic Properties ◽  
Vapor Phase ◽  
Oxygen Pressure ◽  
Zno Nanowires ◽  
Zno Nanostructures ◽  
Uv Sensor ◽  
Zno Nanostructure ◽  
Uv Sensors

AbstractThe present work describes the photoconductivity dependence on ZnO nanostructure UV sensor. ZnO nanostructures were synthesized by direct vapor phase (DVP) technique. ZnO nanowires are of dimensions 30-65 nm in diameter and 5 μm in length. The role of oxygen in deciding the opto-electronic properties of nanostructured ZnO UV sensors was studied.

scholarly journals Nanofabrication using home-made RF plasma coupled chemical vapour deposition system

2014 ◽  
Vol 32 ◽  
pp. 1460342
Author(s):  
Si Ci Ong ◽  
Usman Ilyas ◽  
Rajdeep Singh Rawat
Keyword(s):  
Chemical Vapour ◽  
Chemical Vapor ◽  
Wide Band ◽  
Zno Nanowires ◽  
Operating Conditions ◽  
Rf Plasma ◽  
Zno Nanostructures ◽  
Energetic Ions ◽  
Cvd Method ◽  
Etching Effect

Zinc oxide, ZnO , a popular semiconductor material with a wide band gap (3.37 eV) and high binding energy of the exciton (60 meV), has numerous applications such as in optoelectronics, chemical/biological sensors, and drug delivery. This project aims to (i) optimize the operating conditions for growth of ZnO nanostructures using the chemical vapor deposition (CVD) method, and (ii) investigate the effects of coupling radiofrequency (RF) plasma to the CVD method on the quality of ZnO nanostructures. First, ZnO nanowires were synthesized using a home-made reaction setup on gold-coated and non-coated Si (100) substrates at 950 °C. XRD, SEM, EDX, and PL measurements were used for characterizations and it was found that a deposition duration of 10 minutes produced the most well-defined ZnO nanowires. SEM analysis revealed that the nanowires had diameters ranging from 30-100 mm and lengths ranging from 1-4 µm. In addition, PL analysis showed strong UV emission at 380 nm, making it suitable for UV lasing. Next, RF plasma was introduced for 30 minutes. Both remote and in situ RF plasma produced less satisfactory ZnO nanostructures with poorer crystalline structure, surface morphology, and optical properties due to etching effect of energetic ions produced from plasma. However, a reduction in plasma discharge duration to 10 minutes produced thicker and shorter ZnO nanostructures. Based on experimentation conducted, it is insufficient to conclude that RF plasma cannot aid in producing well-defined ZnO nanostructures. It can be deduced that the etching effect of energetic ions outweighed the increased oxygen radical production in RF plasma nanofabrication.

Preponderant role of pentafluorophenyl moieties for tuning the electronic properties of extended benzodifuran-azomethine derivatives

2021 ◽  
Author(s):  
Chady Moussallem ◽  
Magali Allain ◽  
Frédéric Gohier ◽  
Pierre Frere
Keyword(s):  
Electronic Properties ◽  
Electron Donor ◽  
Electron Acceptor

From a central 3,7-bis(perfluorophenyl)-BDF unit, the extension performed with electron acceptor perfluorophenyl groups and/or electron donor N,N-dimethylamino groups via an imine link leads to symmetrical AAA and DAD or dissymmetrical...

Electronic properties in Ga‐doped CdTe layers grown by metalorganic vapor phase epitaxy

1992 ◽  
Vol 72 (8) ◽  
pp. 3406-3409 ◽  
Author(s):  
Mitsuru Ekawa ◽  
Kazuhito Yasuda ◽  
Touati Ferid ◽  
Manabu Saji ◽  
Akikazu Tanaka
Keyword(s):  
Electronic Properties ◽  
Vapor Phase ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Vapor Phase Epitaxy

Large-scale, single-oriented ZnO nanostructure on h-BN films for flexible inorganic UV sensors

2021 ◽  
Vol 130 (22) ◽  
pp. 223105
Author(s):  
Hongseok Oh ◽  
Youngbin Tchoe ◽  
Heehun Kim ◽  
Jiyoung Yun ◽  
Mingi Park ◽  
...  
Keyword(s):  
Large Scale ◽  
Zno Nanostructure ◽  
Uv Sensors

Assessment of UV Sensors for Flameout Detection

2017 ◽  
Author(s):  
Edouard Bahous ◽  
Ram Srinivasan ◽  
Priyank Saxena ◽  
John Bowen
Keyword(s):  
Response Time ◽  
Detection System ◽  
Signal Strength ◽  
Sensor Response ◽  
System Level ◽  
Fuel Composition ◽  
Engine Load ◽  
Uv Sensor ◽  
Uv Sensors ◽  
Load Conditions

UV sensors were tested to evaluate the response and reliability as a flameout detection system to reduce system level risks. In this study, UV sensors from two manufacturers were tested on high pressure experimental rigs and on a 15MW gas turbine engine with annular diffusion flame combustion system. Tests were run to investigate the effect of fuel composition, engine load, and sensor circumferential position. The effect of each variable on sensor signal strength and response time is presented in this paper. The response time of the sensor is evaluated against the rate of change of combustor pressure and the time for fuel-air mixture to reach lean extinction limit in the primary zone. Results show that the UV sensor response is not affected by engine load, circumferential location of the sensors, or fuel composition down to Wobbe index of 18.7 MJ/Sm3. At lower Wobbe indices, the signal strength decreased significantly. This result has been attributed to the movement of flame location away from the line of sight of the sensor. Furthermore, it was found that the UV sensor responded before the bulk average reactant mixture reached lean blow out fuel-air ratios. When compared to the baseline detection system the UV sensor performs faster at low load conditions (800 milliseconds) but slower at full load conditions (400 milliseconds). Experimental rig testing led to similar conclusions for sensor response time and signal strength. Future testing of UV sensors on hydrogen blends is planned.

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