scholarly journals InGaN/GaN nanoLED Arrays as a Novel Illumination Source for Biomedical Imaging and Sensing Applications

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 892 ◽  
Author(s):  
Jan Gülink ◽  
Steffen Bornemann ◽  
Hendrik Spende ◽  
Matthias Auf der Maur ◽  
Aldo Di Carlo ◽  
...  
Keyword(s):  
Biomedical Imaging ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Sensing Applications ◽  
Device Processing ◽  
Led Array ◽  
Line Contacts ◽  
Processing Optimization ◽  
Illumination Source

Guidelines for the fabrication of nanoscale light-emitting diode arrays (i.e., nanoLED arrays) based on patterned gallium nitride (GaN) with very small dimensions and pitches have been derived in this work. Several challenges during top-down LED array processing have been tackled involving hybrid etching and polymer-based planarization to yield completely insulated highaspect-ratio LED fin structures and support the creation of p-GaN crossing line contacts, respectively. Furthermore, simulations of the light emission patterns were also performed providing hints for enhancing the device designs. As a result, regardless of the required device processing optimization, the developed nanoLED arrays are expected to offer high potential as novel illumination sources in biomedical imaging and sensing applications (e.g., mini compact microscopes and wearable biological/chemical nanoparticle counters)

White light emission from a blue polymer light emitting diode combined with YAG:Ce3+ nanoparticles

2013 ◽  
Vol 211 (3) ◽  
pp. 651-655 ◽  
Author(s):  
Jorge Oliva ◽  
Elder De la Rosa ◽  
Luis Diaz-Torres ◽  
Anvar Zakhidov
Keyword(s):  
White Light ◽  
Light Emission ◽  
Light Emitting Diode ◽  
White Light Emission ◽  
Light Emitting ◽  
Polymer Light Emitting Diode

A Monolithic White-Light LED Based on GaN Doped with Be

2014 ◽  
Vol 93 ◽  
pp. 264-269 ◽  
Author(s):  
Henryk Teisseyre ◽  
Michal Bockowski ◽  
Toby David Young ◽  
Szymon Grzanka ◽  
Yaroslav Zhydachevskii ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
White Light ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Yellow Emission ◽  
Bulk Crystals ◽  
Light Emitting ◽  
Type Conductivity ◽  
P Type ◽  
Colour Rendering

In this communication, the use of gallium nitride doped with beryllium as an efficient converter for white light emitting diode is proposed. Until now beryllium in this material was mostly studied as a potential p-type dopant. Unfortunately, the realization of p-type conductivity in such a way seems impossible. However, due to a very intensive yellow emission, bulk crystals doped with beryllium can be used as light converters. In this communication, it is demonstrated that realisation of such diode is possible and realisation of a colour rendering index is close to that necessary for white light emission.

Miniaturized UV-LED Array Chip Photochemical Vapor Generator Coupled with Point Discharge Optical Emission Spectrometer for Determination of Trace Selenium

2021 ◽  
Author(s):  
Mengtian Li ◽  
Yi Luo ◽  
Zhirong Zou ◽  
Fujian Xu ◽  
Xiaoming Jiang ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Optical Emission ◽  
Nano Tio2 ◽  
Light Emitting ◽  
Uv Led ◽  
Led Array ◽  
Point Discharge ◽  
Photochemical Vapor Generation ◽  
Optical Emission Spectrometer

An ultraviolet light emitting diode (UV-LED) array chip as irradiation source for nano-TiO2 catalyzed photochemical vapor generation (PCVG) was combined with a hollow electrode point discharge microplasma optical emission spectrometer...

Light Emitting Diode with MOS Structures Containing Multiple-Stacked Si Quantum Dots

2007 ◽  
Vol 121-123 ◽  
pp. 557-560 ◽  
Author(s):  
J. Xu ◽  
Katsunori Makihara ◽  
Hidenori Deki ◽  
Yoshihiro Kawaguchi ◽  
Hideki Murakami ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Luminescence Intensity ◽  
Room Temperature ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Infrared Light ◽  
Gate Bias ◽  
Light Emitting ◽  
Mos Structures ◽  
Si Quantum Dots

Light emitting diode with MOS structures containing multiple-stacked Si quantum dots (QDs)/SiO2 was fabricated and the visible-infrared light emission was observed a room temperature when the negative gate bias exceeded the threshold voltage. The luminescence intensity was increased linearly with increasing the injected current density. The possible luminescence mechanism was briefly discussed and the delta P doping was performed to obtain the doped Si QDs and the improvement of EL intensity was demonstrated.

Electrostatic Discharge Characteristics of InGaN/GaN Light-Emitting Diodes with Si-Doped Graded Superlattice

2015 ◽  
Vol 15 (10) ◽  
pp. 7733-7737 ◽  
Author(s):  
Kwanjae Lee ◽  
Cheul-Ro Lee ◽  
Jin Soo Kim ◽  
Jin Hong Lee ◽  
Kee Young Lim ◽  
...  
Keyword(s):  
Light Emission ◽  
Electrostatic Discharge ◽  
Light Emitting Diode ◽  
Emission Spectra ◽  
Small Variation ◽  
Injection Current ◽  
Light Emitting ◽  
Current Voltage ◽  
Gan Led ◽  
Si Doped

We report the influences of a Si-doped graded superlattice (SiGSL) on the electrostatic discharge (ESD) characteristics of an InGaN/GaN light-emitting diode (LED). For comparison, a conventional InGaN/GaN LED (C-LED) was also investigated. The luminous efficacy for the SiGSL-LED was 2.68 times stronger than that for the C-LED at the injection current of 20 mA. The resistances estimated from current–voltage (I–V) characteristic curves were 16.5 and 8.8 Ω for the C-LED and SiGSL-LED, respectively. After the ESD treatment at the voltages of 4000 and 6000 V, there was no significant change in the I–V curves for the SiGSL-LED. Also, there was small variation in the I–V characteristics for the SiGSL-LED at the ESD voltage of 8000 V. However, the I–V curves for the C-LED were drastically degraded with increasing ESD voltage. While the light emission was not observed at the injection current of 20 mA from the C-LED sample after the ESD treatment, the emission spectra for the SiGSL-LED sample were clearly measured with the output powers of 10.47, 9.66, and 7.27 mW for the ESD voltages of 4000, 6000, and 8000 V respectively.

scholarly journals Real-Time Healthcare Data Transmission for Remote Patient Monitoring in Patch-Based Hybrid OCC/BLE Networks

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1208 ◽  
Author(s):  
Moh. Hasan ◽  
Md. Shahjalal ◽  
Mostafa Chowdhury ◽  
Yeong Jang
Keyword(s):  
Real Time ◽  
Light Emitting Diode ◽  
Health Condition ◽  
High Signal ◽  
Network Access ◽  
Light Emitting ◽  
Healthcare Data ◽  
Led Array ◽  
Access Request ◽  
Remote Patient

Research on electronic healthcare (eHealth) systems has increased dramatically in recent years. eHealth represents a significant example of the application of the Internet of Things (IoT), characterized by its cost effectiveness, increased reliability, and minimal human eff ort in nursing assistance. The remote monitoring of patients through a wearable sensing network has outstanding potential in current healthcare systems. Such a network can continuously monitor the vital health conditions (such as heart rate variability, blood pressure, glucose level, and oxygen saturation) of patients with chronic diseases. Low-power radio-frequency (RF) technologies, especially Bluetooth low energy (BLE), play significant roles in modern healthcare. However, most of the RF spectrum is licensed and regulated, and the effect of RF on human health is of major concern. Moreover, the signal-to-noise-plus-interference ratio in high distance can be decreased to a considerable extent, possibly leading to the increase in bit-error rate. Optical camera communication (OCC), which uses a camera to receive data from a light-emitting diode (LED), can be utilized in eHealth to mitigate the limitations of RF. However, OCC also has several limitations, such as high signal-blockage probability. Therefore, in this study, a hybrid OCC/BLE system is proposed to ensure efficient, remote, and real-time transmission of a patient’s electrocardiogram (ECG) signal to a monitor. First, a patch circuit integrating an LED array and BLE transmitter chip is proposed. The patch collects the ECG data according to the health condition of the patient to minimize power consumption. Second, a network selection algorithm is developed for a new network access request generated in the patch circuit. Third, fuzzy logic is employed to select an appropriate camera for data reception. Fourth, a handover mechanism is suggested to ensure efficient network allocation considering the patient’s mobility. Finally, simulations are conducted to demonstrate the performance and reliability of the proposed system.

scholarly journals Illuminance and Starting Distance of the Far Field of LED-Array Luminaire Operated at Short Working Distance

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 360
Author(s):  
Ching-Cherng Sun ◽  
Yi-Syuan Lin ◽  
Tsung-Hsun Yang ◽  
Shih-Kang Lin ◽  
Xuan-Hao Lee ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Light Sources ◽  
Far Field ◽  
Extended Source ◽  
Light Emitting ◽  
High Uniformity ◽  
Led Array ◽  
Working Distance ◽  
Divergent Angle ◽  
Short Working

A luminaire with a light-emitting diode (LED) array can provide hotspot illumination in a short range. Therefore, a design of a luminaire with the largest central illuminance (LCI) and a high uniformity is warranted. In this paper, we present a study of illuminance variation with respect to the distance of an illumination target of a luminaire with LED array. The emission property of the luminous intensity is characterized by the cosine power law or the divergent angle of full width at half maximum (FWHM). A real LED module is designed to create the simulation for different luminaire types. The occurrence of the LCI and the far-field region are observed. Our results demonstrate that the LCI distance remains shorter than the starting distance of the far field (SDFF). To simplify the simulation, we propose the replacement of the real LED module with a point or flat-extended source. Such light sources must be equipped with the specific cosine power factor corresponding to the divergent angle of the FWHM of the LED module. These light sources are acceptable for describing illumination characteristics, including the SDFF. Our results may facilitate the design of LED-array luminaires operated at short working distances, such as reading lighting or illumination in microscopes.

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