Beyond illumination: multifunctional capabilities of a near-ultraviolet multiple quantum well diode array

Area of Science:

• Materials Science
• Optoelectronics
• Solid-State Physics

Background:

• Indium Gallium Nitride/Gallium Nitride (InGaN/GaN) systems are key for near-ultraviolet (UV) light-emitting diodes (LEDs).
• Current research primarily focuses on emission properties like photopolymerization and anti-counterfeiting.
• A need exists to expand the application scope of near-UV LEDs beyond simple emission.

Purpose of the Study:

• To design and demonstrate a novel multifunctional near-UV multiple quantum well (MQW) diode array.
• To integrate emission, photodetector, and wireless optical communication capabilities into a single InGaN/GaN platform.
• To explore advanced applications such as optical image input and robust wireless optical communication.

Main Methods:

• Fabrication of a 4x4 array with 16 near-UV MQW diodes (395-405 nm).
• Characterization of emission (anti-counterfeiting, UV curing) and detection (photodetector) modes.
• Implementation of a convolutional neural network (CNN) for optical character recognition.
• Evaluation of multiple-input multiple-output (MIMO) near-UV wireless optical communication (WLC) performance.
• Testing array robustness under ambient sunlight conditions.

Main Results:

• The array successfully performed traditional UV LED functions (emission).
• In detection mode, the array achieved >96% accuracy in character recognition via CNN.
• Near-UV WLC demonstrated per-pixel data rates up to 40 kHz.
• The array exhibited robustness in strong ambient sunlight.

Conclusions:

• The developed InGaN/GaN MQW array offers integrated multifunctional capabilities.
• This technology expands near-UV LED applications into optical input and anti-interference WLC.
• The findings provide new technological solutions for advanced optoelectronic systems.