Observation of Terahertz Photon-Assisted Tunneling in Triple-Barrier Resonant Tunneling Diodes Integrated with Patch Antenna

Terahertz (THz) photon-assisted tunneling was observed in GaInAs/InAlAs triple-barrier resonant tunneling diodes (RTDs) integrated with patch antennas on InP substrates. The conduction loss of the antenna was reduced by a structure that consists of an Au-coated ground plane, an Au antenna electrode and a thick benzo-cyclo-butane layer as a dielectric between them. Large THz voltages were induced across the RTD with this structure by THz irradiation (frequency f=1.4–3.1 THz), e. g. , 122 mV at an incident power of 76 mW at f=1.4 THz. Current changes due to photon-assisted tunneling with photon absorption and emission were determined. The peak voltage of the current change shifts due to the multiphoton process with increasing incident power. The multiphoton process was remarkable at low irradiation frequency. These measurements were in reasonable agreement with theory.