scholarly journals Influence of Irradiation Time on Structural, Morphological Properties of ZnO-NRs Films Deposited by MW-CBD and Their Photodiode Applications

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Saliha Ilican ◽  
Kamuran Gorgun ◽  
Yasemin Caglar ◽  
Mujdat Caglar
Keyword(s):  
Irradiation Time ◽  
Reverse Current ◽  
Preferred Orientation ◽  
Illumination Intensity ◽  
Zinc Oxide Nanorods ◽  
Morphological Properties ◽  
Wurtzite Phase ◽  
Good Crystallinity ◽  
Current Voltage ◽  
Hexagonal Nanorods

Microwave-assisted chemical bath deposition (MW-CBD) was used to deposit zinc oxide nanorods (ZnO-NRs) films by using different microwave irradiation time. The films exhibit a good crystallinity having a hexagonal wurtzite phase formation. Although the dominant preferred orientation was not observed for the ZnO-5 and ZnO-10, ZnO-8 showed (002) preferred orientation. The emission scanning electron microscope (FESEM) showed almost randomly oriented hexagonal nanorods on the surface. A slight decrease in the length of the observed hexagonal nanorods due to the increase in the irradiation time was observed, changing from 550 nm to 300 nm. The p-Si/n-ZnO-NRs heterojunction photodiodes were fabricated. The current-voltage characteristics of these photodiodes were investigated under dark and different illumination intensity. An increase in the reverse current with increasing illumination intensity confirmed that the fabricated photodiodes exhibited a photoconducting behavior. In addition, the barrier height and series resistance values of the photodiodes were determined from capacitance-voltage measurements.

The Properties Of a-Si:H/c-Si Heterostructures Prepared By 55 kHz Pecvd For Solar Cell Application

1997 ◽  
Vol 485 ◽  
Author(s):  
B. G Budaguan ◽  
A. A. Aivazov ◽  
A. A. Sherchenkov ◽  
A. V Blrjukov ◽  
V. D. Chernomordic ◽  
...  
Keyword(s):  
Crystalline Silicon ◽  
Low Frequency ◽  
Reverse Current ◽  
Chemical Vapor ◽  
Interface State ◽  
State Density ◽  
Solar Cell Application ◽  
Current Voltage ◽  
Frequency Plasma ◽  
Device Applications

AbstractIn this work a-Si:H/c-Si heterostructures with good electronic properties of a-Si:H were prepared by 55 kHz Plasma Enhanced Chemical Vapor Deposition (PECVD). Currentvoltage and capacitance-voltage characteristics of a-Si:H/c-Si heterostructures were measuredto investigate the influence of low frequency plasma on the growing film and amorphous silicon/crystalline silicon boundary. It was established that the interface state density is low enough for device applications (<2.1010 cm−2). The current voltage measurements suggest that, when forward biased, space-charge-limited current determines the transport mechanism in a- Si:H/c-Si heterostructures, while reverse current is ascribed to the generation current in a-Si:H and c-Si depletion layers.

scholarly journals A Study of a-Sic/C-Si(n) Isotype Heterojunctions

1993 ◽  
Vol 16 (1) ◽  
pp. 55-64 ◽  
Author(s):  
N. Georgoulas ◽  
L. Magafas ◽  
A. Thanailakis
Keyword(s):  
Temperature Dependence ◽  
Crystalline Silicon ◽  
Diffusion Mechanism ◽  
Thermionic Emission ◽  
Reverse Current ◽  
Emission Mechanism ◽  
Drift Diffusion ◽  
Si Substrates ◽  
Current Voltage ◽  
Capacitance Voltage

In the present work a study of the electrical properties of heterojunctions between rf sputtered amorphous silicon carbide (a-SiC) thin films and n-type crystalline silicon (c-Si) substrates is reported. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics, as well as the temperature dependence of the current of a-SiC/c-Si(n) heterojunctions were measured. The I-V characteristics of a-SiC/ c-Si(n) heterojunctions exhibit poor rectification properties, with a high reverse current, at higher temperatures (T > 250K), whereas good rectification properties are obtained at lower temperatures (T < 250K). It was found that the a-SiC/c-Si(n) heterojunctions are isotype, suggesting that-the conductivity of a-SiC is n-type. The temperature dependence of the current (from 185K to 320K) showed that the majority carriers of c-Si(n) (i.e. electrons) are transported from c-Si(n) to a-SiC mainly by the thermionic emission mechanism, or by the drift-diffusion mechanism. From C-V measurements of a-SiC/c-Si(n) heterojunctions the electron affinity of a-SiC was found to be X1= 4.20 ± 0.04 eV. Finally, the a-SiC/ c-Si(n) isotype heterojunctions are expected to be interesting devices as infrared

Effect of Annealing Temperature of Magnesium Doped Zinc Oxide Nanorods Growth on Silicon Substrate

2013 ◽  
Vol 26 ◽  
pp. 33-38 ◽  
Author(s):  
Ruziana Mohamed ◽  
Zuraida Khusaimi ◽  
A.N. Afaah ◽  
Aadila Aziz ◽  
Mohamad Hafiz Mamat ◽  
...  
Keyword(s):  
Silicon Substrate ◽  
Annealing Temperature ◽  
Zno Nanorods ◽  
Zinc Oxide Nanorods ◽  
Immersion Method ◽  
Xrd Diffraction ◽  
Zinc Oxides ◽  
Good Crystallinity ◽  
Oxide Nanorods ◽  
Mg Doped

Magnesium (Mg)-doped zinc oxides (ZnO) have been prepared on a silicon substrate by using the solution-immersion method. The nanorods films were annealed at different temperature 0°C, 250°C, 500°C respectively for 1 hour. The XRD diffraction indicated that the Mg-doped ZnO nanorods have good crystallinity with a hexagonal wurzite structure preferentially oriented along the (002) direction. PL spectroscopy at room temperature shows strong UV peaks appearing at 383 nm when annealed at 250°C. The intensity of broad emission peaks increases with increasing annealing temperature to 500°C which is possibility attributed to intrinsic defects.

scholarly journals Exploring the Effect of the Irradiation Time on Photosensitized Dendrimer-Based Nanoaggregates for Potential Applications in Light-Driven Water Photoreduction

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1316 ◽  
Author(s):  
Martínez ◽  
Inostroza-Rivera ◽  
Durán ◽  
Molero ◽  
Bonardd ◽  
...  
Keyword(s):  
Active Sites ◽  
Methyl Viologen ◽  
Irradiation Time ◽  
Pt Nanoparticles ◽  
Morphological Properties ◽  
Fourth Generation ◽  
Self Assembling ◽  
Potential Applications ◽  
Potential Use

Fourth generation polyamidoamine dendrimer (PAMAM, G4) modified with fluorescein units (F) at the periphery and Pt nanoparticles stabilized by L-ascorbate were prepared. These dendrimers modified with hydrophobic fluorescein were used to achieve self-assembling structures, giving rise to the formation of nanoaggregates in water. The photoactive fluorescein units were mainly used as photosensitizer units in the process of the catalytic photoreduction of water propitiated by light. Complementarily, Pt-ascorbate nanoparticles acted as the active sites to generate H2. Importantly, the study of the functional, optical, surface potential and morphological properties of the photosensitized dendrimer aggregates at different irradiation times allowed for insights to be gained into the behavior of these systems. Thus, the resultant photosensitized PAMAM-fluorescein (G4-F) nanoaggregates (NG) were conveniently applied to light-driven water photoreduction along with sodium L-ascorbate and methyl viologen as the sacrificial reagent and electron relay agent, respectively. Notably, these aggregates exhibited appropriate stability and catalytic activity over time for hydrogen production. Additionally, in order to propose a potential use of these types of systems, the in situ generated H2 was able to reduce a certain amount of methylene blue (MB). Finally, theoretical electronic analyses provided insights into the possible excited states of the fluorescein molecules that could intervene in the global mechanism of H2 generation.

Influence of aluminum-doped zinc oxide seeding film on morphological properties of hydrothermally-grown zinc oxide nanorods

2020 ◽  
Vol 59 (3) ◽  
pp. 035502
Author(s):  
Narathon Khemasiri ◽  
Navaphun Kayunkid ◽  
Nathan Soyeux ◽  
Prapakorn Rattanawarinchai ◽  
Sukittiya Jessadaluk ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Zinc Oxide Nanorods ◽  
Morphological Properties ◽  
Oxide Nanorods ◽  
Aluminum Doped Zinc Oxide

Improving Sensitivity of p-n Junction Temperature Sensor by Carrier Lifetime Modification

2008 ◽  
Vol 55-57 ◽  
pp. 517-520
Author(s):  
Amporn Poyai ◽  
E. Ratanaudomphisut ◽  
J. Supadech ◽  
N. Klunngien ◽  
C. Hruanan ◽  
...  
Keyword(s):  
Leakage Current ◽  
Temperature Sensor ◽  
Carrier Lifetime ◽  
Reverse Current ◽  
Junction Temperature ◽  
Carrier Generation ◽  
Current Voltage ◽  
Generation Lifetime

This paper presents the relation between the staring cobalt thickness with carrier generation lifetime, which effects to the sensitivity of p-n junction temperature sensor. The starting cobalt thickness of 12, 20 and 30nm have been used. The carrier generation lifetimes have been calculated from the reverse current-voltage (I-V) characteristics. The highest carrier generation lifetime has been obtained in the case of 12nm starting cobalt thickness. The highest sensitivity of p-n junction temperature sensor has also been observed from the case of 12nm starting cobalt thickness. The sensitivity has been calculated from the relation between leakage current versus temperature. The sensitivity of p-n junction temperature sensor can be improved by increasing carrier generation lifetime.

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