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arXiv · 2004.02710

Critical behavior of the insulator-to-metal transition in Te-hyperdoped Si

Mao Wang·A. Debernardi·Wenxu Zhang·Chi Xu·Ye Yuan·Yufang Xie·Y. Berencén·S. Prucnal·M. Helm·Shengqiang Zhou
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Abstract

Hyperdoping Si with chalcogens is a topic of great interest due to the strong sub-bandgap absorption exhibited by the resulting material, which can be exploited to develop broadband room-temperature infrared photodetectors using fully Si-compatible technology. Here, we report on the critical behavior of the impurity-driven insulator-to-metal transition in Te-hyperdoped Si layers fabricated via ion implantation followed by nanosecond pulsed-laser melting. Electrical transport measurements reveal an insulator-to-metal transition, which is also confirmed and understood by density functional theory calculations. We demonstrate that the metallic phase is governed by a power law dependence of the conductivity at temperatures below 25 K, whereas the conductivity in the insulating phase is well described by a variable-range hopping mechanism with a Coulomb gap at temperatures in the range of 2-50 K. These results show that the electron wave-function in the vicinity of the transition is strongly affected by the disorder and the electron-electron interaction.

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Mao Wang, A. Debernardi, Wenxu Zhang, Chi Xu, Ye Yuan, Yufang Xie, Y. Berencén, S. Prucnal, M. Helm, Shengqiang Zhou. 2020-04-06. Critical behavior of the insulator-to-metal transition in Te-hyperdoped Si. https://doi.org/10.1103/physrevb.102.085204

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