scholarly journals Soft, Wirelessly Powered Humidity Sensor Based on SnO2 Nanowires for Wireless/Wearable Sensor Application

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2176 ◽  
Author(s):  
Gunchul Shin
Keyword(s):  
Electrical Properties ◽  
Humidity Sensor ◽  
Light Emitting Diode ◽  
Chemical Vapor ◽  
Polymer Substrate ◽  
Light Emitting ◽  
Sno2 Nanowires ◽  
Transfer Method ◽  
Soft Polymer ◽  
Response To Water

Humidity, along with temperature, is one of the most important environmental variables in people’s lives. The control of humidity is an important matter that is related to material properties and stability in various industries, as well as basic living. In order to detect humidity, changes in the physical, chemical, and electrical properties of materials related to humidity are used, and studies using various methods are conducted. In this study, a field-effect transistor (FET) device was fabricated on a soft polymer substrate with SnO2 nanowires (NWs), whose electrical properties change in response to water molecules. The SnO2 NWs, synthesized by chemical vapor deposition (CVD), were transferred onto a polymer substrate, using a sliding transfer method. The NW FET device, which was connected to an aluminum (Al)-based radio frequency (RF) receiving antenna, was wirelessly operated as a humidity sensor, based on the change in electrical properties of SnO2 NWs according to the relative humidity (RH). It was configured with a wireless antenna and light emitting diode (LED) indicator to implement a soft wirelessly powered humidity sensor that senses high RH and is expected to be used as a wearable electronic/sensor in the future.

OPTICAL PROPERTIES OF GaInN/GaN MULTI-QUANTUM WELL STRUCTURE AND LIGHT EMITTING DIODE GROWN BY METALORGANIC CHEMICAL VAPOR PHASE EPITAXY

2007 ◽  
Vol 17 (01) ◽  
pp. 81-84
Author(s):  
J. Senawiratne ◽  
M. Zhu ◽  
W. Zhao ◽  
Y. Xia ◽  
Y. Li ◽  
...  
Keyword(s):  
Optical Properties ◽  
Quantum Well ◽  
Stark Effect ◽  
Light Emitting Diode ◽  
Chemical Vapor ◽  
Green Emission ◽  
Luminescence Spectroscopy ◽  
Light Emitting ◽  
Quantum Confined Stark Effect ◽  
Multi Quantum Well

Optical properties of green emission Ga 0.80 In 0.20 N/GaN multi-quantum well and light emitting diode have been investigated by using photoluminescence, cathodoluminescence, electroluminescence, and photoconductivity. The temperature dependent photoluminescence and cathodoluminescence studies show three emission bands including GaInN/GaN quantum well emission centered at 2.38 eV (~ 520 nm). The activation energy of the non-radiative recombination centers was found to be ~ 60 meV. The comparison of photoconductivity with luminescence spectroscopy revealed that optical properties of quantum well layers are strongly affected by the quantum-confined Stark effect.

UV Emission Mechanisms in Quaternary AlInGaN Epilayers and Multiple Quantum Wells

2002 ◽  
Vol 722 ◽  
Author(s):  
Mee-Yi Ryu ◽  
C. Q. Chen ◽  
E. Kuokstis ◽  
J. W. Yang ◽  
G. Simin ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Light Emitting Diode ◽  
Chemical Vapor ◽  
Excitation Power ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Excitation Power Density ◽  
Light Emitting ◽  
Uv Emission ◽  
Alloy Disorder

AbstractWe present the results on investigation and analysis of photoluminescence (PL) dynamics of quaternary AlInGaN epilayers and AlInGaN/AlInGaN multiple quantum wells (MQWs) grown by a novel pulsed metalorganic chemical vapor deposition (PMOCVD). The emission peaks in both AlInGaN epilayers and MQWs show a blueshift with increasing excitation power density. The PL emission of quaternary samples is attributed to recombination of carriers/excitons localized at band-tail states. The PL decay time increases with decreasing emission photon energy, which is a characteristic of localized carrier/exciton recombination due to alloy disorder. The obtained properties of AlInGaN materials grown by a PMOCVD are similar to those of InGaN. This indicates that the AlInGaN system is promising for ultraviolet applications such as the InGaN system for blue light emitting diode and laser diode applications.

High-efficiency vertical-structure GaN-based light-emitting diodes on Si substrates

2018 ◽  
Vol 6 (7) ◽  
pp. 1642-1650 ◽  
Author(s):  
Wenliang Wang ◽  
Yunhao Lin ◽  
Yuan Li ◽  
Xiaochan Li ◽  
Liegen Huang ◽  
...  
Keyword(s):  
High Efficiency ◽  
Light Emitting Diode ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Buffer Layers ◽  
Organic Chemical ◽  
Light Emitting ◽  
Si Substrates ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

High-quality GaN-based light-emitting diode (LED) wafers have been grown on Si substrates by metal–organic chemical vapor deposition by designing epitaxial structures with AlN/Al0.24Ga0.76N buffer layers and a three-dimensional (3D) GaN layer.

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