scholarly journals Hydrothermal Growth of Quasi-Monocrystal ZnO Thin Films and Their Application in Ultraviolet Photodetectors

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yung-Chun Tu ◽  
Shui-Jinn Wang ◽  
Tseng-Hsing Lin ◽  
Chien-Hsiung Hung ◽  
Tsung-Che Tsai ◽  
...  
Keyword(s):  
Annealing Temperature ◽  
Uv Light ◽  
Hydrothermal Growth ◽  
Photoluminescence Spectra ◽  
Zno Film ◽  
Sputtering Deposition ◽  
Photoelectric Properties ◽  
Growth Method ◽  
P Type ◽  
Ultraviolet Photodetectors

Quasi-monocrystal ZnO film grown using the hydrothermal growth method is used for the fabrication of Cu2O/ZnO heterojunction (HJ) ultraviolet photodetectors (UV-PDs). The HJ was formed via the sputtering deposition of p-type Cu2O onto hydrothermally grown ZnO film (HTG-ZnO-film). The effect of annealing temperature in the nitrogen ambient on the photoluminescence spectra of the synthesized ZnO film was studied. The optoelectronic properties of Cu2O/ZnO film with various Cu2O thicknesses (250–750 nm) under UV light (365 nm; intensity: 3 mW/cm2) were determined. The UV sensitivity of the HTG-ZnO-film-based UV-PDs and the sputtered ZnO-film-based UV-PDs were 55.6-fold (SHTG) and 8.8-fold (Ssputter), respectively. The significant gain in sensitivity (SHTG/Ssputter= 630%) of the proposed ZnO-film-based device compared to that for the device based on sputtered film can be attributed to the improved photoelectric properties of quasi-monocrystal ZnO film.

Fabrication and Characterization of ZnO-Based Nano Hetero Structure by Using a 2-Step Hydrothermal Growth Method

2012 ◽  
Vol 476-478 ◽  
pp. 881-885
Author(s):  
Tron Min Chen ◽  
Kai Ming Uang ◽  
Shu Kuo Lin
Keyword(s):  
Uv Light ◽  
Hydrothermal Growth ◽  
Good Sensitivity ◽  
Hetero Structure ◽  
Growth Method ◽  
Nano Rods ◽  
Fabrication And Characterization ◽  
P Type ◽  
Type Nickel

In this study, we reported the fabrication and characterization of a nano hetero junction (NHJ) structure which is synthesized by a 2-step hydrothermal growth (HTG) method. The zinc oxide (ZnO) nano rods (NRs) were grown by the 2-step HTG onto p-type nickel oxide (p-NiO) film e-beam deposited glass substrate to form n-ZnO-NRs/p-NiO NHJs. The electrical properties of the n-ZnO-NRs/p-NiO NHJs show a rectifying behavior of a p-n junction. The optoelectronic properties of the n-ZnO-NRs/ p-NiO NHJs under UV light (366 nm) light with good sensitivity were presented.

scholarly journals Photocatalytic Activity and Optical Properties of Blue Persistent Phosphors under UV and Solar Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
C. R. García ◽  
L. A. Diaz-Torres ◽  
J. Oliva ◽  
M. T. Romero ◽  
P. Salas
Keyword(s):  
Photocatalytic Activity ◽  
Annealing Temperature ◽  
Uv Light ◽  
Solar Irradiation ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Water Cleaning ◽  
Different Temperatures ◽  
The Eu

Blue phosphorescent strontium aluminosilicate powders were prepared by combustion synthesis route and a postannealing treatments at different temperatures. X-ray diffraction analysis showed that phosphors are composed of two main hexagonal phases: SrAl2O4and Sr3Al32O51. The morphology of the phosphors changed from micrograins (1000°C) to a mixture of bars and hexagons (1200°C) and finally to only hexagons (1300°C) as the annealing temperature is increased. Photoluminescence spectra showed a strong blue-green phosphorescent emission centered atλem=455 nm, which is associated with4f65d1→4f6  (8S7/2)transition of the Eu2+. The sample annealed at 1200°C presents the highest luminance value (40 Cd/m2) with CIE coordinates (0.1589, 0.1972). Also, the photocatalytic degradation of methylene blue (MB) under UV light (at 365 nm) was monitored. Samples annealed at 1000°C and 1300°C presented the highest percentage of degradation (32% and 38.5%, resp.) after 360 min. In the case of photocatalytic activity under solar irradiation, the samples annealed at 1000°C, 1150°C, and 1200°C produced total degradation of MB after only 300 min. Hence, the results obtained with solar photocatalysis suggest that our powders could be useful for water cleaning in water treatment plants.

UV Light Driven Photoelectric Properties of ZnO Film to Humidity

2020 ◽  
Vol 20 (12) ◽  
pp. 7516-7521
Author(s):  
Zhijun Zou ◽  
Tan Tan ◽  
Gaohua Liao ◽  
Chang Li ◽  
Xiaoxiang Sun ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Bias Voltage ◽  
Screen Printing ◽  
Photoelectric Property ◽  
Uv Light ◽  
The Other ◽  
Time Dependent ◽  
Zno Film ◽  
Photoelectric Properties ◽  
Other Hand

UV light driven photoelectric properties of ZnO film to humidity were researched. ZnO film was prepared through the method of screen printing sustained on Al2O3 substrate. ZnO was characterized by XRD, FE-SEM and EDX. The time-dependent UV light driven photoelectric properties of ZnO were investigated by exposing it to different bias voltages and different relative humidity (20% RH, 40% RH, 60% RH and 80% RH). On one hand, the photoelectric properties of ZnO increased with the augmenting of bias voltage, which shows that a higher bias causes more separation of carriers. On the other hand, the photocurrent decreased with the increase in relative humidity, which shows that bigger humidity results in smaller photoelectric property. To discuss these results, corresponding possible illustrations for the photoelectric properties under different conditions were proposed.

scholarly journals Effects of annealing temperature on the characteristics of Ga-doped ZnO film metal-semiconductor-metal ultraviolet photodetectors

2013 ◽  
Vol 113 (8) ◽  
pp. 084501 ◽  
Author(s):  
L. C. Yang ◽  
R. X. Wang ◽  
S. J. Xu ◽  
Z. Xing ◽  
Y. M. Fan ◽  
...  
Keyword(s):  
Annealing Temperature ◽  
Zno Film ◽  
Metal Semiconductor Metal ◽  
Doped Zno ◽  
Ultraviolet Photodetectors

Immobilization of ZnO Suspension on Glass Substrate to Remove Filtration During the Removal of Remazol Red R from Aqueous Solution

2016 ◽  
Vol 12 (6) ◽  
pp. 4127-4133
Author(s):  
Nazmul Kayes ◽  
Jalil Miah ◽  
Md. Obaidullah ◽  
Akter Hossain ◽  
Mufazzal Hossain
Keyword(s):  
Aqueous Solution ◽  
Glass Substrate ◽  
Uv Light ◽  
Aqueous Suspension ◽  
Light Irradiation ◽  
Zno Films ◽  
Light Sources ◽  
Zno Film ◽  
Semiconductor Oxides ◽  
Remazol Red

Photodegradation of textile dyes in the presence of an aqueous suspension of semiconductor oxides has been of growing interest. Although this method of destruction of dyes is efficient, the main obstacle of applying this technique in the industry is the time and cost involving separation of oxides from an aqueous suspension. In this research, an attempted was made to develop ZnO films on a glass substrate by simple immobilization method for the adsorption and photodegradation of a typical dye, Remazol Red R (RRR) from aqueous solution. Adsorption and photodegradation of  RRR were performed in the presence of glass supported ZnO film. Photodegradation of the dye was carried out by varying different parameters such as the catalyst dosage, initial concentrations of RRR, and light sources. The percentage of adsorption as well as photodegradation increased with the amount of ZnO, reaches a maximum and then decreased. Maximum degradation has been found under solar light irradiation as compared to UV-light irradiation. Removal efficiency was also found to be influenced by the pre-sonication of ZnO suspension.

Improvement of the Specific Contact Resistance on P-Type 4H-SiC by Using a Highly P-Typed Doped 4H-SiC Layer Selectively Grown by VLS Transport

2014 ◽  
Vol 806 ◽  
pp. 57-60
Author(s):  
Nicolas Thierry-Jebali ◽  
Arthur Vo-Ha ◽  
Davy Carole ◽  
Mihai Lazar ◽  
Gabriel Ferro ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Ohmic Contacts ◽  
Schottky Barrier Height ◽  
Annealing Temperature ◽  
Process Condition ◽  
Specific Contact Resistance ◽  
High Doping Level ◽  
Annealing Temperatures ◽  
Specific Contact ◽  
P Type

This work reports on the improvement of ohmic contacts made on heavily p-type doped 4H-SiC epitaxial layer selectively grown by Vapor-Liquid-Solid (VLS) transport. Even before any annealing process, the contact is ohmic. This behavior can be explained by the high doping level of the VLS layer (Al concentration > 1020 cm-3) as characterized by SIMS profiling. Upon variation of annealing temperatures, a minimum value of the Specific Contact Resistance (SCR) down to 1.3x10-6 Ω.cm2 has been obtained for both 500 °C and 800 °C annealing temperature. However, a large variation of the SCR was observed for a same process condition. This variation is mainly attributed to a variation of the Schottky Barrier Height.

Fabrication of ZnO homojunction-based color-switchable bidirectional LEDs by using a hydrothermal growth method

2017 ◽  
Vol 5 (36) ◽  
pp. 9479-9487 ◽  
Author(s):  
Sung-Doo Baek ◽  
Yoann Porte ◽  
Yun Cheol Kim ◽  
Jae-Min Myoung
Keyword(s):  
Hydrothermal Growth ◽  
Growth Method

ZnO homojunction-based LEDs, with variable emission wavelengths depending on bias polarity, have been fabricated using a simple hydrothermal growth method.

scholarly journals Behavior of W and WSix Contact Metallization on n- and p- Type GaN

1999 ◽  
Vol 4 (S1) ◽  
pp. 684-690
Author(s):  
X. A. Cao ◽  
F. Ren ◽  
J. R. Lothian ◽  
S. J. Pearton ◽  
C. R. Abernathy ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Annealing Temperature ◽  
Specific Contact Resistance ◽  
Ohmic Behavior ◽  
Contact Metallization ◽  
Specific Contact ◽  
Heavily Doped ◽  
Sputter Deposited ◽  
Optimum Annealing Temperature ◽  
P Type

Sputter-deposited W-based contacts on p-GaN (NA∼1018 cm−3) display non-ohmic behavior independent of annealing temperature when measured at 25°C. The transition to ohmic behavior occurs above ∼250°C as more of the acceptors become ionized. The optimum annealing temperature is ∼700°C under these conditions. These contacts are much more thermally stable than the conventional Ni/Au metallization, which shows a severely degraded morphology even at 700°C. W-based contacts may be ohmic as-deposited on very heavily doped n-GaN, and the specific contact resistance improves with annealing up to ∼900°C.

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