Special Topic on LED Simulation

Abstract: This topic employs Nuwa TCAD to simulate the optoelectronic characteristics of GaN multi-quantum well LEDs, V-pit LEDs, Micro-LEDs, and OLEDs. It demonstrates the structure modeling process for LED devices in Nuwa TCAD, including relevant model parameter settings and characteristic results. The objective is to enable users to fully understand and master the operation and usage of Nuwa TCAD software, allowing them to perform simulations and optimization designs for various types of LEDs.

Since the 1990s, with a series of significant breakthroughs in the growth process of GaN-based semiconductor materials, the third-generation semiconductor materials, represented by GaN, have gradually emerged. GaN-based semiconductor materials can produce efficient blue, green, and white light-emitting diodes (LEDs). As a new type of efficient solid-state light source, LEDs are characterized by long life, energy savings, and environmental friendliness. They are widely applied in large-screen color displays, automotive lighting and traffic signals, multimedia displays, optical communications, and are expected to replace incandescent and fluorescent lamps in the future, leading to a new revolution in human lighting history.

With continuous improvements in growth processes and manufacturing technology, LEDs have gradually expanded toward deep ultraviolet and red-light emissions, while also advancing in miniaturization and micro-sizing, such as UV LEDs, Mini-LEDs, and Micro-LEDs. This has led to increasing demand in fields like sterilization, wearable devices, AR/VR displays, and flexible screens. However, the LED industry still faces many challenges, such as low P-doping concentration in AlGaN/GaN/AlN materials, high defect concentration in epitaxial growth, polarization effects, Micro-LED sidewall damage, small-size effects, heat dissipation, mass transfer, and yield issues. These challenges lead to low luminous efficiency and high production costs, impacting practical applications. Therefore, enhancing LED and OLED luminous efficiency and reducing costs remain essential goals within the LED field.

This topic primarily introduces the simulation process for InGaN/GaN multi-quantum well LEDs, V-pit LEDs, Micro-LEDs, and OLEDs, covering device structure, model settings, and result output. It includes the carrier transport process in multi-quantum wells, the construction of V-pit structures, Micro-LED damage effects, and exciton diffusion and recombination mechanisms in OLEDs. The goal is to enable users to understand device simulation technology and leverage it to address existing issues in LEDs or develop LED device structures with superior performance.

2. Simulation Tools

This topic uses Nuwa TCAD semiconductor process and device simulation software to simulate LED/OLED devices. Nuwa TCAD includes models for polarization effects, defect models, SRH recombination, Auger recombination, radiative recombination, non-equilibrium quantum transport, self-consistent multi-quantum well modeling, exciton diffusion, exciton recombination, and self-heating. These models enable the accurate simulation of optoelectronic characteristics of GaN-based LEDs and OLEDs by describing physical phenomena like defects, polarization, non-radiative recombination, and carrier hopping.