Ultraviolet light emitting diodes using non-polar A-plane AlGaN multiple quantum wells

ABSTRACTIn this paper, we report the growth and fabrication of non-polar A-plane AlGaN multiple quantum well based ultraviolet light emitting diodes (UV-LEDs). The LEDs were grown on R-plane sapphire substrates using molecular beam epitaxy (MBE). The Current-voltage characteristics of the fabricated devices demonstrated rectifying behavior with a series resistance of 38 ohms. An electro-luminescence emission at 338 nm was obtained.

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A Comparative Study of Thermal Metrology Techniques for Ultraviolet Light Emitting Diodes

Journal of Heat Transfer ◽

10.1115/1.4024359 ◽

2013 ◽

Vol 135 (9) ◽

Cited By ~ 2

Author(s):

Shweta Natarajan ◽

Yishak Habtemichael ◽

Samuel Graham

Keyword(s):

Raman Spectroscopy ◽

Comparative Study ◽

Quantum Wells ◽

Ultraviolet Light ◽

Light Emitting Diodes ◽

Multiple Quantum ◽

Forward Voltage ◽

Light Emitting ◽

Uv Leds ◽

Ultraviolet Light Emitting Diodes

Methods used to measure the temperature of AlxGa1−xN based ultraviolet light emitting diodes (UV LEDs) are based on optical or electrical phenomena that are sensitive to either local, surface, or average temperatures within the LED. A comparative study of the temperature rise of AlxGa1−xN UV LEDs measured by micro-Raman spectroscopy, infrared (IR) thermography, and the forward voltage method is presented. Experimental temperature measurements are provided for UV LEDs with micropixel and interdigitated contact geometries, as well as for a number of different packaging configurations. It was found that IR spectroscopy was sensitive to optical properties of the device layers, while forward voltage method provided higher temperatures, in general. Raman spectroscopy was used to measure specific layers within the LED, showing that growth substrate temperatures in the flip-chip LEDs agreed more closely to IR measurements while layers closer to the multiple quantum wells (MQWs) agreed more closely with Forward Voltage measurements.

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Enhanced Radiative Recombination Rate by Local Potential Fluctuation in InGaN/AlGaN Near-Ultraviolet Light-Emitting Diodes

Applied Sciences ◽

10.3390/app9050871 ◽

2019 ◽

Vol 9 (5) ◽

pp. 871 ◽

Cited By ~ 4

Author(s):

Abu Islam ◽

Dong-Soo Shim ◽

Jong-In Shim

Keyword(s):

Potential Energy ◽

Ultraviolet Light ◽

Light Emitting Diodes ◽

Internal Quantum Efficiency ◽

Multiple Quantum Well ◽

Multiple Quantum ◽

Energy Fluctuation ◽

Light Emitting ◽

Near Ultraviolet ◽

Ultraviolet Light Emitting Diodes

We investigate the differences in optoelectronic performances of InGaN/AlGaN multiple-quantum-well (MQW) near-ultraviolet light-emitting diodes by using samples with different indium compositions. Various macroscopic characterizations have been performed to show that the strain-induced piezoelectric field (FPZ), the crystal quality, and the internal quantum efficiency increase with the sample’s indium composition. This improved performance is owing to the carrier recombination at relatively defect-free indium-rich localized sites, caused by the local in-plane potential-energy fluctuation in MQWs. The potential-energy fluctuation in MQWs are considered to be originating from the combined effects of the inhomogeneous distribution of point defects, FPZ, and indium compositions.

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