Modeling excitation-dependent bandstructure effects on InGaN light-emitting diode efficiency

Area of Science:

• Optoelectronics
• Semiconductor Physics
• Materials Science

Background:

• Wurtzite quantum wells exhibit carrier density-dependent bandstructure properties.
• Screening of the quantum-confined Stark effect (QCSE) is a key factor influencing these changes.
• Accurate modeling of InGaN light-emitting diodes (LEDs) requires accounting for these dynamic bandstructure variations.

Purpose of the Study:

• To develop and describe an approach for incorporating carrier density-dependent bandstructure changes into an InGaN LED model.
• To investigate the impact of these bandstructure modifications on device performance.
• To predict the internal quantum efficiency (IQE) of InGaN LEDs as a function of excitation.

Main Methods:

• Solving Poisson and k·p equations within the envelope approximation to compute bandstructure for various carrier densities.
• Utilizing the computed bandstructure information as input for a dynamical model.
• Modeling populations in momentum-resolved electron and hole states.
• Applying the developed approach to simulate device IQE versus excitation.

Main Results:

• The study successfully integrates carrier density effects into an InGaN LED model.
• The approach allows for the prediction of how bandstructure changes affect device performance.
• Simulations demonstrate the modeling of internal quantum efficiency as a function of excitation.

Conclusions:

• The developed approach provides a robust method for modeling InGaN LEDs with realistic bandstructure properties.
• Understanding carrier density-dependent effects is crucial for optimizing LED efficiency.
• This work contributes to the accurate simulation and design of high-performance optoelectronic devices.