Far-infrared and terahertz emitting diodes based on graphene/black-P and graphene/MoS₂ heterostructures

Abstract

We propose the far-infrared and terahertz emitting diodes (FIR-EDs and THz-EDs) based on the graphene-layer/black phosphorus (GL/b-P) and graphene-layer/MoS2 (GL/MoS2) heterostructures with the lateral hole and vertical electron injection and develop their device models. In these EDs, the GL serves as an active region emitting the FIR and THz photons. Depending on the material of the electron injector, the carriers in the GL can be either cooled or heated dictated by the interplay of the vertical electron injection and optical phonon recombination. The proposed EDs based on GL/b-P heterostructures can be efficient sources of the FIP and THz radiation operating at room temperature.

Theoretical analysis of injection driven thermal light emitters based on graphene encapsulated by hexagonal boron nitride

“…In deriving equation ( 22), we have neglected the photon recycling and the photon accumulation inside the device (i.e., the resonant properties of the heterostructure). In the case of small (µ e + µ h )/T , equations ( 21) and ( 22) coincide with the pertinent formulae in our recent paper [46] [in which the injection of relatively low energy carriers was considered, so that(µ e + µ h )/T can be large].…”

“…Our mathematical model (which is the generalized version of those used previously [44][45][46], see also more early works [31,59]) corresponds to the following scenario: (i) The injected hot holes transfer their energy partially to different optical phonon modes (intra-valley and inter-valley phonons in the GL and the interface phonons. (emitting the cascades of these phonons) and partially to the 2DEHP via the injected hole collisions with the 2DEHP electrons and holes; (ii) The 2DEHP heated by the injected holes transfer the excessive energy to the optical phonon systems [60]; (iii) The optical phonon system transfers the energy to the acoustic phonons (lattice) due to the anharmonic optical and interface phonons decay [61][62][63][64][65];…”

“…Heterostructures with graphene layers (GLs) are promising building blocks for infrared and terahertz photodetectors [1-14], optical modulators [15][16][17][18], plasmonic and frequency multiplication devices [19][20][21][22][23][24][25][26][27][28], and lasers and light-emitting diodes [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44] (including those based on hybrid GL/black phosphorous devices [45,46]). The realization of the onchip monolithic nanoscale relatively simple light sources for high-bandwidth inter-and intra-chip connections is still a challenging problem [47].…”

“…Another option is to use the combined carrier injection (the injection of relatively cold carriers from the side contact(s) and the vertical injection of the not too hot carriers from the top contact). This concept was recently applied to the GL heterostructures [44][45][46] aiming to realize the interband population inversion in the GLs for its use for far-infrared and terahertz lasing or superluminescence (the combined carrier injection is widely used in the standard vertical-cavity surface emitting heterostructure lasers).…”

Terahertz radiation and the skin: a review

“…19 Here, we should also mention emerging THz-wave solid-state emitters and detectors, which are based on different two-dimensional materials, such as graphene and related heterostructures, as well as on novel physical principles of operation. [20][21][22][23] The majority of studies on biological samples have been performed using THz pulsed radiation because it yields broader information than CW-radiation does (see below). The applied techniques are THz pulsed spectroscopy (TPS) and THz pulsed imaging (TPI); the schematic of a pulsed spectrometer is shown in Fig.…”