Integration of continuous graphene with periodic ferroelectric domains for adaptive terahertz photodetector

Abstract

Graphene plasmons exhibit significant potential for applications in terahertz (THz) detectors due to their fascinating interactions between electromagnetic radiation and matter. However, the excitation and manipulation of graphene plasmons in continuous graphene that is free of patterned technique remain considerable challenges. Here, we present an adaptive wavelength-sensitive terahertz detector, which comprises continuous graphene integrated onto a ferroelectric thin film featuring periodic polarization domains. This designed device demonstrates the capability to absorb THz waves without the need for an external bias voltage, attributed to the high confinement of surface plasmons at the graphene-ferroelectric interface. By reconfiguring an interweaving squared ferroelectric domain array with alternating upward and downward polarizations, our devices theoretically achieve an ultrahigh responsivity of 17.56 A W^-1 and a specific detectivity of 1.11 × 10¹¹ Jones at room temperature. Furthermore, we demonstrate the feasibility of utilizing these photodetectors for spectrum reconstruction applications in portable spectrometers across a broad frequency range of 4.97 to 7.85 THz and achieving a spectral resolution of up to 0.02 THz when integrated with mathematical algorithms.