Device Simulation on GaN‐LED Operating in Noncarrier Injection Mode for Performance Improvement by Enhancing the Tunneling Effect in Multiquantum Wells

Noncarrier injection (NCI) operation mode is an emerging driving mode for nanoscale light‐emitting diodes (LEDs) for application in nanopixel light‐emitting displays. However, the luminescence intensity of the NCI‐LED with traditional epitaxial structure is relatively low because of the absence of external carrier injection. Therefore, improving the luminescence intensity by optimizing the epitaxial structure of the LED is an important technical measure. In this work, the tunneling behavior of the NCI‐LED under reverse bias, which plays a key role in increasing the luminescence intensity, is studied through modeling and simulation. The dynamic variation of carrier concentration in each voltage cycle is studied to explore the working process of the NCI‐LED. Results show that the luminescence output of the NCI‐LED is highly sensitive to doping concentrations, and reducing the number of multiquantum wells can increase the probability of interband tunneling so as to improve dramatically the carrier number contributing to luminescence. This simulation work can deepen the understanding of the NCI mode and serve as an important guidance for the rational design of the NCI‐LEDs. Finite element simulation model of a GaN‐LED operating in noncarrier injection mode is established. It is found that the luminescence output of the NCI‐LED is highly sensitive to doping concentrations, and reducing the multiquantum wells number can increase the probability of interband tunneling so as to improve the luminescence intensity. The highest luminescence intensity occurs in the device with a single quantum well.