Dirac Semimetal Heterostructures: 3D Cd₃As₂ on 2D Graphene

Abstract

Dirac semimetal is an emerging class of quantum matters, ranging from 2D category, such as, graphene and surface states of topological insulator to 3D category, for instance, Cd As and Na Bi. As 3D Dirac semimetals typically possess Fermi-arc surface states, the 2D-3D Dirac van der Waals heterostructures should be promising for future electronics. Here, graphene-Cd As heterostructures are fabricated through direct layer-by-layer stacking. The electronic coupling results in a notable interlayer charge transfer, which enables us to modulate the Fermi level of graphene through Cd As . A planar graphene p-n-p junction is achieved by selective modification, which demonstrates quantized conductance plateaus. Moreover, compared with the bare graphene device, the graphene-Cd As hybrid device presents large nonlocal signals near the Dirac point due to the charge transfer from the spin-polarized surface states in the adjacent Cd As . The results enrich the family of van der Waals heterostructure and should inspire more studies on the application of Dirac/Weyl semimetals in spintronics.

Design strategies for two‐dimensional material photodetectors to enhance device performance

“…[95][96][97] Such novel materials also need to combine with other materials to promote entire performance. 39,73,98,99 Qiao et al incorporated a similar hexagonal symmetry Bi 2 Te 3 with graphene as shown in Figure 5G, the photodetector demonstrated a strong and broadband responsivity reach telecommunication band (35 A/W and extend to 1550 nm depicted in Figure 5H). 73…”

Thickness-Controlled Three-Dimensional Dirac Semimetal for Scalable High-Performance Terahertz Optoelectronics

“…The remarkable high electron mobility 48 and almost vanishing gap energy 49 render Cd 3 As 2 as a patent system for studying Dirac physics and exotic carrier transport. 50 The large thermoelectric power factor, 25 high carrier mobility, 34,51 large Fermi velocity, 23 and resistance against oxidation 52 have been reported in the Cd 3 As 2 system, providing a step forward in the strategy for optoelectronic applications. 53 In this work, Dirac semimetal Cd 3 As 2 films are derived via the molecular beam epitaxy (MBE) route.…”

Ultrasensitive and Self‐Powered Terahertz Detection Driven by Nodal‐Line Dirac Fermions and Van der Waals Architecture

“…Among such, 3D Dirac semimetal Cd 3 As 2 has spawned highly sensitive photodetection with a simple configuration in the mid‐infrared region, and the graphene‐Cd 3 As 2 hybrid system through layer‐by‐layer stacking exhibits the quantized conductance plateaus by local and nonlocal signals near the Dirac point. [ 17 ] Additionally, due to the mid‐infrared bulk photovoltaic effect in the Weyl semimetal TaAs, the shift current separated from the photo‐thermoelectric effect is revealed via the polarization measurement. [ 18 ] The shift current of Weyl semimetal TaIrTe 4 is boosted up by the singularities of the Berry curvature at the vicinity of Weyl nodes, opening up novel feasibility to explore exotic photoresponse through the single‐particle excitation process in the mid‐infrared regime.…”