Mid- and far-infrared localized surface plasmon resonances in chalcogen-hyperdoped silicon

TL;DR

This paper demonstrates mid- and far-infrared localized surface plasmon resonances in Te-hyperdoped silicon, enabling CMOS-compatible infrared sensing and potentially revolutionizing integrated plasmonic sensor manufacturing.

Contribution

It introduces a novel approach to achieve infrared plasmonic resonances in silicon using hyperdoping with tellurium, compatible with existing CMOS technology.

Findings

Mid-infrared LSPR observed in Te-hyperdoped Si films

LSPR spectral range extended to far-infrared with antenna arrays

Potential for integrated CMOS-compatible plasmonic sensors

Abstract

Plasmonic sensing in the infrared region employs the direct interaction of the vibrational fingerprints of molecules with the plasmonic resonances, creating surface-enhanced sensing platforms that are superior than the traditional spectroscopy. However, the standard noble metals used for plasmonic resonances suffer from high radiative losses as well as fabrication challenges, such as tuning the spectral resonance positions into mid- to far-infrared regions, and the compatibility issue with the existing complementary metal-oxide-semiconductor (CMOS) manufacturing platform. Here, we demonstrate the occurrence of mid-infrared localized surface plasmon resonances (LSPR) in thin Si films hyperdoped with the known deep-level impurity tellurium. We show that the mid-infrared LSPR can be further enhanced and spectrally extended to the far-infrared range by fabricating two-dimensional arrays of micrometer-sized antennas in a Te-hyperdoped Si chip. Since Te-hyperdoped Si can also work as an infrared photodetector, we believe that our results will unlock the route toward the direct integration of plasmonic sensors with the one-chip CMOS platform, greatly advancing the possibility of mass manufacturing of high-performance plasmonic sensing systems.