Novel thin-GaN LED structure adopted micro abraded surface to compare with conventional vertical LEDs in ultraviolet...

Area of Science:

• Materials Science
• Optoelectronics
• Solid-State Physics

Background:

• Conventional vertical injection light-emitting diodes (V-LEDs) face challenges with electrode absorption and current spreading.
• Improving efficiency and reducing droop in ultraviolet light-emitting diodes (UV-LEDs) is crucial for advanced applications.

Purpose of the Study:

• To fabricate novel thin-gallium nitride (GaN)-based UV-LEDs (NTG-LEDs) with enhanced performance.
• To investigate the impact of electrode placement and fabrication techniques on device efficiency and light output power.

Main Methods:

• Fabrication of NTG-LEDs utilizing wafer bonding, laser lift-off, dry etching, and textured surface techniques.
• Implementation of a same-side PN electrode configuration to minimize absorption and improve current spreading.
• Performance characterization under varying current densities (700 mA and 1,500 mA).

Main Results:

• NTG-LEDs demonstrated an 18.3% increase in light output power and a 20.0% enhancement in external quantum efficiency (EQE) at 700 mA compared to V-LEDs.
• At 1,500 mA, light output power and EQE were enhanced by 27.4% and 27.2%, respectively.
• Efficiency droop was reduced by over 15% at high current levels.

Conclusions:

• The novel thin-GaN-based UV-LEDs offer superior light output power and EQE compared to conventional devices.
• The developed fabrication techniques, particularly the same-side electrode placement, effectively mitigate absorption and enhance current spreading.
• These NTG-LEDs represent a significant advancement in UV-LED technology, with improved efficiency and reduced droop for demanding applications.