UV Light Emitter

A strong research and big achievement by Dr. M Ajmal Khan research group.

Link of the article is given.

Twisted stacking of two-dimensional van der Waals (vdW) semiconductors creates moiré superlattices, which provides unprecedented control over quantum states and their light-matter interactions. We demonstrate that a simple twist interface between two single-crystalline bulks of hexagonal boron nitride (hBN) creates moiré quantum wells (QWs) embedded in a three-dimensional vdW structure. hBN moiré QWs strongly confine charge carriers under both optical excitation and electrical injection. Despite their indirect bandgap, they emit intense deep-ultraviolet luminescence in the extreme wavelength bands from 215 to 240 nanometers, exceeding that of state-of-the-art conventional aluminum gallium nitride (AlGaN) multiple QWs by more than an order of magnitude. Furthermore, the twist angle control allows wide tunability of luminescence energy and efficiency in moiré QWs.

https://www.science.org/doi/10.1126/science.aeb2095

New Research about far UVC AlGaN-based LED

• This study unveils a novel dual-distributed polarization strategy in both n-AlGaN electron injection layer (EIL) and p-AlGaN hole injection layer (HIL) of 229 nm far-UVC LEDs.

• Both 3D electrons and 3D holes are exploited for the enhanced carrier injection toward the multi-quantum-well.

•The dual-distributed polarized LED demonstrates significantly enhanced recombination rates, reduced carrier leakages, and an IQE of 80% with minimal droop at 60 A/cm².

www.sciencedirect.com

The most informative talk about AlGaN-based UVB LED.
Dr. Muhammad Ajmal Khan (wazir)
Riken, Japan.

Invited Talk: Advances and Challenges in Transparent AlGaN UVB LEDs By M. Ajmal Khan, Riken CSW 2023 Mercury Pollution from Fluorescent Lamps and Mercury UV Lamp is hazardous to human lives and nature. Pesticides have the potential to contaminate our air, af...

Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm[1] (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun.