Models of terahertz and infrared devices based on graphene/black-AsP heterostructures

Abstract

The gapless energy spectrum of the graphene layers (GLs) enables the interband absorption and emission of photons and plasmons in the terahertz (THz) and infrared (IR) spectral range. The energy of the emerging the black-phosphorus (b-P), black-arsenic (b-As), and the compounds (b-AsxP1-x) varies from 0.15 to 1.7 eV, depending on the number of the atomic sheets and the component relative content. Due to a strong anisotropy of the b-P and b-As, the ratios of the carrier effective masses in different in-plain directions are very large. One of the crucial properties of the GL heterostructures with the b-P, b-As, and b-AsxP1-x barrier layers are associated with the GL Dirac point corresponding to the energy gap in the barriers. Combination of GLs with the b-P, b-As, and b-AsxP1-x layers opens new prospects for the novel THz and IR devices, in particular, GL-based photodetectors, electro-optical modulators, and sources of THz/IR radiation, including the lasers with the GL active region.