We demonstrate that GaN formed in a Nanowall Network (NwN) morphology can overcome fundamental limitations in optoelectronic devices, and enable high light extraction and effective Mg incorporation for efficient p-GaN. We report the growth of Mg doped GaN Nanowall network (NwN) by plasma assisted molecular beam epitaxy (PA-MBE) that is characterized by Photoluminescence (PL) spectroscopy, Raman spectroscopy, high-resolution X-ray diffraction (HR-XRD), X-ray photoelectron spectroscopy (XPS) and Secondary ion mass spectroscopy (SIMS). We record a photo-luminescence enhancement (≈3.2 times) in lightly doped GaN as compared to that of undoped NwN. Two distinct (and broad) blue luminescence peaks appears at 2.95 and 2.7 eV for the heavily doped GaN (Mg >1020 atoms cm−3), of which the 2.95 eV peak is sensitive to annealing is observed. XPS and SIMS measurements estimate the incorporated Mg concentration to be 1020 atoms cm−3 in GaN NwN morphology, while retaining its band edge emission at ≈ 3.4 eV. A higher Mg accumulation towards the GaN/Al2O3 interface as compared to the surface was observed from SIMS measurements.
@article{arxiv.1611.10263,
title = {GaN Nanowall Network: A new possible route to obtain efficient p-GaN and enhanced light extraction},
author = {Sanjay Kumar Nayak and Mukul Gupta and S. M. Shivaprasad},
journal= {arXiv preprint arXiv:1611.10263},
year = {2016}
}