ReSi2 thin-film infrared detectors

Abstract

Two types of thin-film infrared-sensing devices have been investigated using the narrow band-gap semiconductor, rhenium disilicide (Eg~0.1 eV). These are the ReSi2/n-Si heterojunction internal photoemission (HIP) detector and the ReSi2 thin-film photoconductor. The HIP device was found to be rectifying and to obey a Fowler-type law with a long-wavelength cutoff of ~2.1 μm (0.59 eV) at room temperature. In hopes of approaching the fundamental limit for a ReSi2-based photonic detector, ~12 μm (0.1 eV), the ReSi2 photoconductor was explored. Indeed, the spectral response (measured at 10 K) of the ohmic photoconductor was found to extend to 6 μm (the present limit of our measurement equipment), with no indication of a detection cutoff.