The effect of infrared plasmon on the performance of Si-based THz detectors

Abstract

Plasmons in metals have great impact on light emission, propagation, and detection in visible and infrared light wave frequencies. To explore plasmonic effect on the THz detection, both a backside-illuminated and a topside-illuminated blocking impurity band (BIB) THz detectors are developed and significant influence of plasmonic effect on the performance of BIB THz detectors is observed. The plasmonic effect in the heavily doped semiconductor layer of BIB THz detectors causes high reflectance of THz radiation which curtails the detection frequencies of the backside-illuminated BIB detectors. However, due to the advantages of flip-chip package and high quantum efficiency, the dark current, the responsivity, and the detectivity of the backside-illuminated detector shows superior characteristics to the topside-illuminated detector. The performance of the THz detector could be further improved with the suppression of the plasmonic effect.