Efficiency enhancement of GaN based light-emitting diodes with an n-i-p type last quantum barrier

Abstract

This paper proposes a GaN-based light-emitting diode based on an n-i-p terminal quantum barrier structure that is easy to implement in epitaxy, which can enhance electron confinement and improve hole injection efficiency. Existing GaNbased light-emitting diodes, due to the electron blocking layer (EBL) formed by inserting a wide band gap AlGaN material between the active region and the p-type hole injection layer, cannot effectively confine electrons, and also suppresses multiple quantum wells (MQWs) and Hole injection in the p-type region caused by the polarization field in the EBL. In order to improve the performance of GaN-based LEDs, better suppress electron leakage in the active region and increase the hole injection efficiency in the p-type region, a new design of the terminal quantum barrier was carried out, specifically n-GaN n-GaN (1×1018cm-3)-i-GaN-p-GaN (5×1018cm-3) terminal quantum barrier structure, the thickness of the n, i and p layers in the barrier structure are 4 nm, 5 nm and 4 nm, respectively. This paper uses simulation method to verify the terminal quantum barrier structure. The electrical and optical performance of the GaNbased MQW LED with conventional structure and the LED based on the n-i-p terminal quantum barrier structure were compared, including physical indicators such as output optical power, threshold voltage, and hole injection concentration. The simulation results show that, compared with the traditional structure, the LED with the nip terminal quantum barrier structure has higher output light power and lower threshold voltage, and significantly increases the hole concentration in the active area, which is more effective in suppressing Electronic leaks. The analysis results show that the strong reverse electrostatic field in the nip terminal quantum barrier structure can effectively enhance the electron confinement in the active region, suppress electron leakage and improve the p-type hole injection efficiency. In summary, it is shown that the nip terminal quantum barrier structure can be Effectively improve the performance of LEDs, showing better performance than conventional devices.