Terahertz rectifier exploiting electric field-induced hot-carrier effect in asymmetric nano-electrode

Abstract

Rectifiers have been used to detect electromagnetic waves with very low photon energies. In these rectifying devices, different methods have been utilized, such as adjusting the bandgap and the doping profile, or utilizing the contact potential of the metal-semiconductor junction to produce current flow depending on the direction of the electric field. In this paper, it is shown that the asymmetric application of nano-electrodes to a metal-semiconductor-metal (MSM) structure can produce such rectification characteristics, and a terahertz (THz) wave detector based on the nano-MSM structure is proposed. Integrated with a receiving antenna, the fabricated device detects THz radiation up to a frequency of 1.5 THz with responsivity and noise equivalent power of 10.8 V/W and [Formula: see text] respectively, estimated at 0.3 THz. The unidirectional current flow is attributed to the thermionic emission of hot carriers accelerated by the locally enhanced THz field at the sharp end of the nano-electrode. This work not only demonstrates a new type of THz detector but also proposes a method for manipulating ultrafast charge-carrier dynamics through the field enhancement of the nano-electrode, which can be applied to ultrafast photonic and electronic devices.

Low Contact Resistivity and Interfacial Behavior of p-Type NbFeSb/Mo Thermoelectric Junction

“…32 However, the absence of the fundamental knowledge on interface physical property dramatically hinders the development of TE semiconductor industry. Actually, the issue about interface contact has already been deeply studied in the field of silicon based semiconductor industry, such as MOSFET, 33 diode rectifier 34,35 and so on. An Ohmic contact is often required to reduce the contact resistivity between Si substrate and metal electrode.…”

“…However, the absence of the fundamental knowledge on interface physical property dramatically hinders the development of TE semiconductor industry. Actually, the issue about interface contact has already been deeply studied in the field of silicon based semiconductor industry, such as MOSFET, diode rectifier , and so on. An Ohmic contact is often required to reduce the contact resistivity between Si substrate and metal electrode. , To realize this type of contact, many methods have been successfully applied, such as the matching of work function between semiconductor and metal, and tunneling effect by the high doping level in the semiconductor …”