We report on the insulator-to-metal transition in Se-hyperdoped Si layers driven by manipulating the Se concentration via non-equilibrium material processing, i.e. ion implantation followed by millisecond-flash lamp annealing. Electrical transport measurements reveal an increase of carrier concentration and conductivity with increasing Se concentration. For the semi-insulating sample with Se concentrations below the Mott limit, quantitative analysis of the temperature dependence of conductivity indicates a variable-range hopping mechanism with an exponent of s = 1/2 rather than 1/4, which implies a Coulomb gap at the Fermi level. The observed insulator-to-metal transition is attributed to the formation of an intermediate band in the Se-hyperdoped Si layers.
@article{arxiv.1707.09207,
title = {Realizing the insulator-to-metal transition in Se-hyperdoped Si via non-equilibrium material processing},
author = {F. Liu and S. Prucnal and Y. Berencén and Z. Zhang and Y. Yuan and Y. Liu and R. Heller and R. Boettger and L. Rebohle and W. Skorupa and M. Helm and S. Zhou},
journal= {arXiv preprint arXiv:1707.09207},
year = {2017}
}
Comments
10 pages, 4 figures, accepted by J. Phys. D: Appl. Phys