Precision engineered semimetal-semiconductor diodes for mm-wave and THz rectifiers

Small signal detection of upper mm-wave (>100 GHz) and sub mm (up to 1 THz) radiation has become a topic of great interest. This work presents a new room-temperature zero-bias rectifier that significantly simplifies detector design, mitigates current induced flicker and burst noise, and eliminates bias circuitry and related noise, leading to an inexpensive square-law detector with noise floor ∼10^-12 W/Hz¹2./ Our devices are all epitaxial MBE grown rectifier diodes consisting of an ErAs semimetal film grown in-situ on Si-doped InAlGaAs on InP substrates. The small lattice mismatch (2.1 %) in this material system allows the ErAs to be grown as a dislocation-free single crystal for sufficiently thin layers over semiconductor epi-layers. The contact is thermodynamically stable, robust, and eliminates the possibility of oxide formation at the Schottky interface.