[Invited] This paper reviews recent advances on the concepts of graphene/black-phosphorene-arsenic two-dimensional heterostructures for terahertz (THz) and infrared (IR) detectors and emitters focusing on our proposal, device modeling, and future prospects. Due to the gapless energy spectrum of the graphene layers (GLs), the interband absorption and emission of photons and plasmons in the GLs takes place in wide spectral range, including the THz and IR ranges. The energy gap of the emerging black-Phosphorus (b-P), black-Arsenic (b-As), and the compounds b-P1-xAsx varies from 0.15 to 1.2 eV, depending on the number of the atomic layers and the composite fraction of x. Combining GLs with the b-P, b-As, and b- P1-xAsx layers gives rise to various performance boosting effects in the THz detectors and light sources. © 2025 SPIE.