Vertical Hot-electron Terahertz Detectors Based on Black-As1?xPx/graphene/black-As1?yPy Heterostructures

Abstract

We propose and evaluate vertical hot-electron terahertz (THz) detectors based on black-As 1−x P x /graphene/black-As 1−y P y (b-AsP/G/b-AsP) heterostructures. The operation of these detectors is associated with the thermionic emission of the electrons heated in the graphene layer (G-layer) by incoming THz radiation stimulating the electron injection from the emitter, i.e., with the hot-electron bolometric mechanism. The combination of the effective electron heating in the G-layer with the features of the b-As 1−x P x and b-As 1−y P y band structures with a proper relation between the b-P fractions, x and y (x ≥ y), might result in the high photoconductive gain and detector responsivity of the proposed detectors. As discussed, these detectors can surpass the similar bolometric detectors based on graphene-based heterostructures with relatively high energy barriers for the electrons and holes in the G-layers and the bolometric detectors based on III-V quantum wells.

Modulation characteristics of uncooled graphene photodetectors

“…The steady-state bolometric characteristics of the uniform GL and the GLs with the region patterned into the GL nanowires (nanoribbons) were evaluated previously [9,12]. As it was predicted a long time ago [21], the inclusion of the vertical and lateral barrier regions between the photosensitive standard quantum wells [25][26][27] and between the GLs in the GL-based hot-carrier bolometers with the vertical structure [28,29] generally leads to the responsivity enhancement. The barriers between the carrier puddles and the lateral quantum dots in GLs [13,16] can play a similar role.…”