Enhanced microLED efficiency via strategic pGaN contact geometries

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Micro light-emitting diodes (microLEDs) are advanced display technologies.
• Efficient power output is critical for microLED performance.
• Gallium Nitride (GaN) based devices are widely used in optoelectronics.

Purpose of the Study:

• Investigate the impact of p-type Gallium Nitride (pGaN) contact size on microLED power output efficiency.
• Model and validate the relationship between pGaN contact dimensions and device performance.
• Determine optimal pGaN contact geometries for various operating conditions.

Main Methods:

• Utilized device modeling and simulation techniques.
• Fabricated microLED devices for experimental validation.
• Systematically varied microLED die sizes and pGaN contact dimensions.

Main Results:

• Increasing microLED die size improved output power by 17% in models and 70% in fabricated devices.
• Optimized power output for constant-size microLEDs varied with pGaN contact size and current density.
• Smaller pGaN contacts favored lower current densities, while larger contacts were better at higher densities.

Conclusions:

• Shrinking pGaN contact size is generally preferential for maximizing microLED efficiency by suppressing surface recombination.
• The optimal pGaN contact size depends on the desired operational brightness and current density.
• Careful consideration of contact geometry is essential for further microLED efficiency improvements.