Modulation of far-infrared light transmission by graphene-silicon Schottky junction

Tunable conductive properties of graphene in terahertz and far-infrared regimes provide a prominent way to control electromagnetic waves. In this paper, we explore the photon-electric properties of the graphene-silicon heterostructure and its application in modulating the transmission of far-infrared light. Experimentally, we show this structure will give rise to different transmission modulation ratios with amplitudes varying from tens to few percentages, dependent on the operation wavelength. The modulation effect gradually decreases and saturates within wavenumbers 1000-2000 cm−1 influenced by the pump light power. The diode transmission behavior is explicitly interpreted in terms of the Schottky junction formed between the graphene-silicon interface. The results give a further deep understanding of the electromagnetic behavior of graphene in the far-infrared region that may be integrated for potential applications.