Plasmon-enhanced deep ultraviolet Micro-LED arrays for solar-blind communications

Area of Science:

• Optoelectronics
• Materials Science
• Nanotechnology

Background:

• Deep ultraviolet (DUV) Micro-light emitting diodes (Micro-LEDs) face limitations in modulation bandwidth and efficiency.
• Localized surface plasmon resonance (LSPR) offers a potential mechanism for optical enhancement in semiconductor devices.

Purpose of the Study:

• To investigate the use of LSPR-enhanced aluminum nanotriangle arrays (NTAs) to improve the modulation bandwidth and internal quantum efficiency (IQE) of DUV Micro-LEDs.
• To explore the impact of LSPR coupling on carrier dynamics and light emission in DUV Micro-LEDs.

Main Methods:

• Fabrication of high-density Al NTAs using self-assembled nanospheres.
• Transfer of Al NTAs onto the p-AlGaN region of DUV Micro-LEDs to achieve LSPR coupling.
• Characterization of photoluminescence (PL) intensity, carrier lifetime, and electroluminescence to evaluate performance enhancements.

Main Results:

• A 2.5-fold enhancement in PL intensity was observed.
• Internal quantum efficiency (IQE) is estimated to increase by 15-20% due to the plasmonic effect.
• Carrier lifetime decreased from 1.15 ns to 0.82 ns, indicating accelerated spontaneous emission.
• The -3 dB modulation bandwidth of 6×6 DUV Micro-LED arrays increased from 180 MHz to 300 MHz at 200 A/cm².

Conclusions:

• LSPR coupling using Al NTAs effectively enhances the performance of DUV Micro-LEDs.
• The observed improvements in IQE and modulation bandwidth demonstrate the potential of LSPR for next-generation DUV optoelectronic devices.
• Further optimization of LSPR integration could lead to even greater enhancements in DUV Micro-LEDs.