Optimization of p-cladding layer utilizing polarization doping for Blue-Violet InGaN laser diodes

This work presents an in-depth investigationof the characteristics and challenges of visible InGaN laser diodes (LDs) equipped with top cladding constructed from graded AlGaN polarization-doped p-type layers. Our research demonstrates the successful achievement of highly efficient electrical conductivity within the p-type layers, along with a high slope efficiency of laser diodes reaching up to around 1.5 W/A.We attribute this value to the relatively low optical losses of 5–7 cm−1, resulting from both the optimized structural design and reduced overlap of Mg containing layers with optical mode. Furthermore, we provide compelling evidence indicating that the utilization of a single slope AlGaN profile yields enhanced electrical properties when compared to a multiple gradient approach. Our preliminary findings underscore the indispensability of thin layers of Mg-doped materials, serving as both the electron-blocking layer and the subcontact layer.