Deep-Ultraviolet Micro-LEDs Exhibiting High Output Power and High Modulation Bandwidth Simultaneously

Area of Science:

• Optoelectronics
• Semiconductor Devices
• Wireless Communication

Background:

• Deep-ultraviolet (DUV) solar-blind communication (SBC) offers advantages over visible-light communication, including non-line-of-sight propagation and reduced background noise.
• Aluminum Gallium Nitride (AlGaN)-based DUV micro-light-emitting diodes (µ-LEDs) are promising light sources for DUV-SBC due to their compact size, low power needs, and high modulation capabilities.

Purpose of the Study:

• To develop a DUV-SBC light source capable of simultaneously achieving high output power, high modulation bandwidth, and high data rates for long-haul communication systems.
• To introduce and validate a parallel-arrayed planar (PAP) approach for fabricating DUV µ-LEDs that meet these demanding requirements.

Main Methods:

• Fabrication of interconnected PAP DUV µ-LEDs with a micrometer-scale active emission mesa.
• Characterization of the µ-LEDs' output power, power density, wall-plug efficiency (WPE), and modulation bandwidth.

Main Results:

• The developed PAP DUV µ-LEDs (25 µm diameter) achieved an output power of 83.5 mW at 230 mA, with a power density of 405 W cm⁻².
• A wall-plug efficiency (WPE) of 4.7% was recorded at 155 mA.
• A high -3 dB modulation bandwidth of 380 MHz was demonstrated, indicating suitability for high-speed communication.

Conclusions:

• The proposed PAP approach successfully addresses the need for high-performance DUV µ-LEDs for SBC applications.
• These devices represent a reliable platform for developing high-modulation-bandwidth wireless communication systems.
• The high output power and efficiency also make these LEDs suitable for bio-elimination applications.