scholarly journals Development of a Toluene Detector Based on Deep UV Absorption Spectrophotometry Using Glass and Aluminum Capillary Tube Gas Cells with a LED Source

Micromachines ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 193 ◽  
Author(s):  
Sulaiman Khan ◽  
David Newport ◽  
Stéphane Le Calvé
Keyword(s):  
Gas Flow ◽  
Capillary Tube ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Uv Absorption ◽  
Glass Capillary ◽  
Light Emitting ◽  
Uv Led ◽  
3D Printed ◽  
Deep Uv

A simple deep-ultraviolet (UV) absorption spectrophotometer based on ultraviolet light-emitting diode (UV LED) was developed for the detection of air-borne toluene with a good sensitivity. A fiber-coupled deep UV-LED was employed as a light source, and a spectrometer was used as a detector with a gas cell in between. 3D printed opto-fluidics connectors were designed to integrate the gas flow with UV light. Two types of hollow core waveguides (HCW) were tested as gas cells: a glass capillary tube with aluminum-coated inner walls and an aluminum capillary tube. The setup was tested for different toluene concentrations (10–100 ppm), and a linear relationship was observed with sensitivities of 0.20 mA·U/ppm and 0.32 mA·U/ppm for the glass and aluminum HCWs, respectively. The corresponding limits of detection were found to be 8.1 ppm and 12.4 ppm, respectively.

scholarly journals Suppression of “volcano” morphology and parasitic defect luminescence in AlGaN-based deep-UV light-emitting diode epitaxy

2019 ◽  
Vol 13 ◽  
pp. 102285 ◽  
Author(s):  
Chia-Yen Huang ◽  
Tsung-Yen Liu ◽  
Shih-Ming Huang ◽  
Kai-Hsiang Chang ◽  
Tsu-Ying Tai ◽  
...  
Keyword(s):  
Uv Light ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Deep Uv ◽  
Defect Luminescence

Current-induced degradation process in (In)AlGaN-based deep-UV light-emitting diode fabricated on AlN/sapphire template

2020 ◽  
Vol 109 ◽  
pp. 110352 ◽  
Author(s):  
Pradip Dalapati ◽  
Kosuke Yamamoto ◽  
Takashi Egawa ◽  
Makoto Miyoshi
Keyword(s):  
Uv Light ◽  
Light Emitting Diode ◽  
Degradation Process ◽  
Light Emitting ◽  
Deep Uv

Advances towards deep-UV light emitting diode technologies

2021 ◽  
Author(s):  
M. Kneissl ◽  
G. Cardinali ◽  
J. Enslin ◽  
M. Guttmann ◽  
C. Kuhn ◽  
...  
Keyword(s):  
Uv Light ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Deep Uv

Origins and suppressions of parasitic emissions in ultraviolet light-emitting diode structures

2010 ◽  
Vol 25 (6) ◽  
pp. 1037-1040 ◽  
Author(s):  
Weihuang Yang ◽  
Shuping Li ◽  
Hangyang Chen ◽  
Dayi Liu ◽  
Junyong Kang
Keyword(s):  
Quantum Wells ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Multiple Quantum ◽  
Light Emitting ◽  
Force Microscopy ◽  
Uv Led ◽  
Hole Blocking Layer ◽  
To Come ◽  
P Type

The AlGaN-based ultraviolet (UV) light-emitting diode (LED) structures with AlN as buffer were grown on sapphire substrate by metalorganic vapor-phase epitaxy (MOVPE). A series of cathodoluminescence (CL) spectra were measured from the cross section of the UV-LED structure using point-by-point sampling to investigate the origins of the broad parasitic emissions between 300 and 400 nm, and they were found to come from the n-type AlGaN and AlN layers rather than p-type AlGaN. The parasitic emissions were effectively suppressed by adding an n-type AlN as the hole-blocking layer. Electroluminescence (EL) and atomic force microscopy (AFM) measurements have revealed that the interface abruptness and crystalline quality of the UV-LED structure are essential for the achievement of the EL emissions from the multiple quantum wells (MQWs).

scholarly journals Photocatalytic Degradation of 2-Chlorophenol Using Ag-Doped TiO2Nanofibers and a Near-UV Light-Emitting Diode System

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Ju-Young Park ◽  
In-Hwa Lee
Keyword(s):  
Phase Transformation ◽  
Photocatalytic Degradation ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Sol Gel ◽  
Order Equation ◽  
Light Emitting ◽  
First Order ◽  
Uv Led ◽  
Diode System

This report investigated the photocatalytic degradation of 2-chlorophenol using TiO2nanofibers and Ag-doped TiO2nanofibers, synthesized using the sol-gel and electrospinning techniques, and an ultraviolet light-emitting diode (UV-LED) system as a UV light source. The crystallite size of the Ag-doped TiO2nanofibers was smaller than that of the TiO2nanofibers, because silver retrained phase transformation not only controls the phase transformation but also inhibits the growth of anatase crystallites. The activation energies for the grain growth of the TiO2nanofibers and the Ag-doped TiO2nanofibers were estimated to be 20.84 and 27.01 kJ/mol, respectively. The photocatalytic degradation rate followed a pseudo-first-order equation. The rate constants (k) of the TiO2nanofibers and the Ag-doped TiO2nanofibers were 0.056 and 0.144 min−1, respectively.

Surface plasmon coupling for suppressing p-GaN absorption and TM-polarized emission in a deep-UV light-emitting diode

2015 ◽  
Vol 40 (18) ◽  
pp. 4229 ◽  
Author(s):  
Yang Kuo ◽  
Chia-Ying Su ◽  
Chieh Hsieh ◽  
Wen-Yen Chang ◽  
Chu-An Huang ◽  
...  
Keyword(s):  
Surface Plasmon ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Plasmon Coupling ◽  
Light Emitting ◽  
Surface Plasmon Coupling ◽  
Polarized Emission ◽  
Deep Uv

Advances in group III-nitride-based deep UV light-emitting diode technology

2010 ◽  
Vol 26 (1) ◽  
pp. 014036 ◽  
Author(s):  
M Kneissl ◽  
T Kolbe ◽  
C Chua ◽  
V Kueller ◽  
N Lobo ◽  
...  
Keyword(s):  
Uv Light ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Group Iii ◽  
Deep Uv ◽  
Group Iii Nitride
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