Finding suitable p-type dopants, as well as reliable doping and characterization methods for the emerging wide bandgap semiconductor β-Ga2O3 could strongly influence and contribute to the development of the next generation of power electronic. In this work, we combine easily accessible ion implantation, diffusion and nuclear transmutation methods to properly incorporate the Cd dopant into the β-Ga2O3 lattice, being subsequently characterized at the atomic scale with the Perturbed Angular Correlation (PAC) technique and Density Functional Theory (DFT) simulations. The acceptor character of Cd in β-Ga2O3 is demonstrated, with Cd sitting in the octahedral Ga site in the negative charge state, showing no evidence of polaron deformations nor extra point defects nearby. Furthermore, thermally activated free electrons were observed for temperatures above ~648 K with an activation energy of 0.54(1) eV. At lower temperatures the local electron transport is dominated by a tunneling process between defect levels and the Cd probe.
@article{arxiv.1908.09569,
title = {Cd acceptors in $Ga_2O_3$, an atomistic view},
author = {M. B. Barbosa and J. G. Correia and K. Lorenz and A. S. Fenta and J. Schell and R. Teixeira and E. Nogales and B. Méndez and A. Stroppa and J. P. Araújo},
journal= {arXiv preprint arXiv:1908.09569},
year = {2019}
}
Comments
11 pages, 7 figures, including Supplementary Material; Corrected affiliations