Utilization of polarization-inverted AlInGaN or relatively thinner AlGaN electron blocking layer in InGaN-based blue–violet laser diodes

Abstract

Polarization-induced downward band-bending at the interface between the last quantum barrier (QB) and electron blocking layer (EBL) potentially reduce the effective barrier height and thus may increase the electron leakage in InGaN-based blue–violet laser diodes (LDs). In this work, LD structures with a specially designed polarization-inverted AlInGaN EBL or with a relatively thin ternary Al0.2Ga0.8N EBL are proposed, and their influences on device characteristics are evaluated numerically by using the lastip simulation program. The results indicate that for LDs with proposed EBLs, the problem induced by electric field and the downward band-bending at the interface between the last QB and EBL is alleviated, which results in a reduction of the electron leakage and an improvement of the performances of LDs.