scholarly journals Thickness Study of Er-Doped Magnesium Zinc Oxide Diode by Spray Pyrolysis

Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 454 ◽  
Author(s):  
Yu-Ting Hsu ◽  
Che-Chi Lee ◽  
Wen-How Lan ◽  
Kai-Feng Huang ◽  
Kuo-Jen Chang ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Light Intensity ◽  
Surface Morphology ◽  
Spray Pyrolysis ◽  
Green Light ◽  
Oxide Thickness ◽  
Magnesium Nitrate ◽  
Light Spectrum ◽  
Magnesium Zinc Oxide ◽  
Erbium Doped

Erbium-doped magnesium zinc oxides were prepared through spray pyrolysis deposition at 450 °C with an aqueous solution containing magnesium nitrate, zinc acetate, erbium acetate, and indium nitrate precursors. Diodes with different erbium-doped magnesium zinc oxide thicknesses were fabricated. The effect of erbium-doped magnesium zinc oxide was investigated. The crystalline structure and surface morphology were analyzed using X-ray diffraction and scanning electron microscopy. The films exhibited a zinc oxide structure, with (002), (101), and (102) planes and tiny rods in a mixed hexagonal flakes surface morphology. With the photoluminescence analyses, defect states were identified. The diodes were fabricated via a metallization process in which the top contact was Au and the bottom contact was In. The current–voltage characteristics of these diodes were characterized. The structure resistance increased with the increase in erbium-doped magnesium zinc oxide thickness. With a reverse bias in excess of 8 V, the light spectrum, with two distinct green light emissions at wavelengths of 532 nm and 553 nm, was observed. The light intensity that resulted when using a different operation current of the diodes was investigated. The diode with an erbium-doped magnesium zinc oxide thickness of 230 nm shows high light intensity with an operational current of 80 mA. The emission spectrum with different injection currents for the diodes was characterized and the mechanism is discussed.

scholarly journals On the Nitrogen Doping in Erbium and Nitrogen Codoped Magnesium Zinc Oxide Diode by Spray Pyrolysis

Crystals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 34
Author(s):  
Chun-An Chen ◽  
Yu-Ting Hsu ◽  
Wen-How Lan ◽  
Kai-Feng Huang ◽  
Kuo-Jen Chang ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Nitrogen Content ◽  
Spray Pyrolysis ◽  
Film Surface ◽  
Magnesium Nitrate ◽  
Injection Current ◽  
Light Spectrum ◽  
High Concentration ◽  
Magnesium Zinc Oxide ◽  
Optimal Injection

Diodes with an erbium and nitrogen codoped magnesium zinc oxide (MgZnO:Er,N) active layer were fabricated by spray pyrolysis on Si substrate with aqueous solutions including magnesium nitrate, zinc acetate, erbium acetate, ammonium acetate, and indium nitrate precursors. Diodes with different nitrogen content in their precursor were prepared and their properties were investigated. With scanning electron microscopy, film surface with mixed hexagonal flakes and tiny blocks was characterized for all samples. Certain morphologies varied for samples with different N contents. In the photoluminescence analyses, the intensity of the oxygen-related defects peak increased with the increasing of nitrogen content. The diodes were fabricated with an Au and In deposition on the top and backside. The diode current–voltage as well as capacitance–voltage characteristics were examined. An ununiformed n-type concentration distribution with high concentration near the interface in the MgZnO:Er,N layer was characterized for all samples. Diodes with high nitrogen content exhibit reduced breakdown voltage and higher interface concentration characteristics. Under reversed bias conditions with an injection current of 50 mA, a light spectrum with two distinct green emissions around wavelengths 532 and 553 nm was observed. A small spectrum variation was characterized for diodes prepared from different nitrogen content. The diode luminescence characteristics were examined and the diode prepared from N/Zn=1 in the precursor showed an optimal injection current-to-luminescence property. The current and luminescence properties of the diode were characterized and discussed.

Electrical study of indium doped magnesium zinc oxide by spray pyrolysis

2015 ◽  
Author(s):  
TzuYang Lin ◽  
WeiHsuan Hsu ◽  
ChunYi Lee ◽  
ShengChung Huang ◽  
YuXuan Ding ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Spray Pyrolysis ◽  
Magnesium Zinc Oxide ◽  
Electrical Study

Conductivity Study of Nitrogen-Doped Magnesium Zinc Oxide Prepared by Spray Pyrolysis

2015 ◽  
Vol 4 (3) ◽  
pp. 223-226 ◽  
Author(s):  
Tzu-Yang Lin ◽  
Yu-Ting Hsu ◽  
Lung-Chien Chen ◽  
Mu-Chun Wang ◽  
Wei-Hsuan Hsu ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Spray Pyrolysis ◽  
Magnesium Zinc Oxide ◽  
Nitrogen Doped

scholarly journals Blue as an Underrated Alternative to Green: Photoplethysmographic Heartbeat Intervals Estimation under Two Temperature Conditions

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4241
Author(s):  
Evgeniia Shchelkanova ◽  
Liia Shchapova ◽  
Alexander Shchelkanov ◽  
Tomohiro Shibata
Keyword(s):  
Blue Light ◽  
Characteristic Point ◽  
Biological Effects ◽  
Green Light ◽  
Estimation Accuracy ◽  
Lower Sensitivity ◽  
Light Spectrum ◽  
Cardiovascular Parameter ◽  
Temperature Conditions ◽  
Characteristic Points

Since photoplethysmography (PPG) sensors are usually placed on open skin areas, temperature interference can be an issue. Currently, green light is the most widely used in the reflectance PPG for its relatively low artifact susceptibility. However, it has been known that hemoglobin absorption peaks at the blue part of the spectrum. Despite this fact, blue light has received little attention in the PPG field. Blue wavelengths are commonly used in phototherapy. Combining blue light-based treatments with simultaneous blue PPG acquisition could be potentially used in patients monitoring and studying the biological effects of light. Previous studies examining the PPG in blue light compared to other wavelengths employed photodetectors with inherently lower sensitivity to blue, thereby biasing the results. The present study assessed the accuracy of heartbeat intervals (HBIs) estimation from blue and green PPG signals, acquired under baseline and cold temperature conditions. Our PPG system is based on TCS3472 Color Sensor with equal sensitivity to both parts of the light spectrum to ensure unbiased comparison. The accuracy of the HBIs estimates, calculated with five characteristic points (PPG systolic peak, maximum of the first PPG derivative, maximum of the second PPG derivative, minimum of the second PPG derivative, and intersecting tangents) on both PPG signal types, was evaluated based on the electrocardiographic values. The statistical analyses demonstrated that in all cases, the HBIs estimation accuracy of blue PPG was nearly equivalent to the G PPG irrespective of the characteristic point and measurement condition. Therefore, blue PPG can be used for cardiovascular parameter acquisition. This paper is an extension of work originally presented at the 42nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

Visible Light Emission from Erbium Doped Yttria Stabilized Zirconia

2003 ◽  
Vol 789 ◽  
Author(s):  
Michael Cross ◽  
Walter Varhue
Keyword(s):  
Band Gap ◽  
Light Emission ◽  
Green Light ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Rare Earth Ion ◽  
Device Structure ◽  
Insulating Layer ◽  
Light Emitting ◽  
Erbium Doped

ABSTRACT: One of the major shortcomings of silicon (Si) as a semiconductor material is its inability to yield efficient light emission. There has been a continued interest in adding rare earth ion impurities such as erbium (Er) to the Si lattice to act as light emitting centers. The low band gap of Si however has complicated this practice by quenching and absorbing this possible emission. Increasing the band gap of the host has been successfully tried in the case of gallium nitride (GaN) [1] and Si-rich oxide (SRO) [2] alloys. A similar approach has been tried here, where Er oxide (ErOx) nanocrystals have been formed in a yttria stabilized zirconia (YSZ) host deposited on a Si (100) substrate. The YSZ is deposited as a heteroepitaxial, insulating layer on the Si substrate by a reactive sputtering technique. The Er is also incorporated by a sputtering process from a metallic target and its placement in the YSZ host can be easily controlled. The device structure formed is a simple metal contact/insulator/phosphor sandwich. The device has been found to emit visible green light at low bias voltages. The advantage of this material is that it is much more structured than SiO2 which can theoretically lead to higher emission intensity.

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