Abstract
The dopant distribution and surface and structural properties of Er- and Eu-doped GaN samples were investigated using atom probe tomography (APT) and atomic force microscopy (AFM). Erbium accumulation within host GaN threading dislocations was directly detected by APT allowing for the dislocations to be imaged in three dimensions. In addition, photoluminescence spectroscopy with high lateral resolution, by means of scanning near-field optical microscopy, was performed on Eu-doped GaN samples. By combining these results with AFM mappings of the same area, it was concluded that Eu3+ ions also accumulate at threading dislocations. Moreover, high-resolution surface profiles of both samples show that even dilute doping (<0.2%) of Eu and Er has a significant influence on the growth morphology of the GaN host material and the nature of the threading dislocations within it. Transmission electron microscopy techniques were used to show the influence of rare-earth incorporation on the growth of GaN lattice and the propagation of threading dislocations.
| Original language | English |
|---|---|
| Article number | 013102 |
| Journal | Journal of Applied Physics |
| Volume | 127 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 7 2020 |
Funding
The MOCVD growth effort is supported by the Army Research Office (ARO) (Grant No. W911NF-09-1-0275) and U.S. Army CERDEC (Grant No. W15P7T-07-D-P040). H.X.J. would like to acknowledge the support of Whitacre endowed chairs through the AT&T Foundation. This work was partly supported by a Grant-in-Aid for Scientific Research (S) (No. JP24226009) from the Japan Society for the Promotion of Science and the Murata Science Foundation, as well as another Grant-in-Aid for Specially Promoted Research (JP18H05212) from the Japan Society for the Promotion of Science. APT was conducted at ORNL\u2019s Center for Nanophase Materials Sciences (CNMS), which is a U.S. DOE Office of Science User Facility. This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/ downloads/doe-public-access-plan).