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arXiv · 1707.09207

Realizing the insulator-to-metal transition in Se-hyperdoped Si via non-equilibrium material processing

F. Liu·S. Prucnal·Y. Berencén·Z. Zhang·Y. Yuan·Y. Liu·R. Heller·R. Boettger·L. Rebohle·W. Skorupa·M. Helm·S. Zhou
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Abstract

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.

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F. Liu, S. Prucnal, Y. Berencén, Z. Zhang, Y. Yuan, Y. Liu, R. Heller, R. Boettger, L. Rebohle, W. Skorupa, M. Helm, S. Zhou. 2017-07-28. Realizing the insulator-to-metal transition in Se-hyperdoped Si via non-equilibrium material processing. https://doi.org/10.1088/1361-6463/aa82f9

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