Enhanced near-infrared absorption in Au-hyperdoped Si: interplay between mid-gap states and plasmon resonance.

Detecting near-infrared (NIR) light with high efficiency is crucial for photodetectors that are applied in optical communication systems. Si hyperdoped with deep-level impurities provides a monolithic platform for infrared optoelectronics with room-temperature operation at telecommunication wavelengths. In this work, we present strongly enhanced NIR absorption via the hybridization between plasmon resonance and mid-gap states in Au-hyperdoped Si layers, prepared by ion implantation and pulsed laser melting.