Weyl-Semimetal TaIrTe₄/Si Nanostructures for Self-Powered Schottky Photodetectors

Abstract

Weyl semimetal-based photodetectors have attracted great attention due to their high performance in fast, self-powered, and ultra-broad-band photodetection. However, the inherent large dark current of the semimetal hinders further improvement of their performance. Thus, it is urgent to utilize a van der Waals (vdW) heterojunction strategy to effectively decrease the dark current and separate the carriers. Herein, a vertical Schottky junction photodetector based on Weyl semimetal TaIrTe4 and n-Si nanostructures has been studied. The junction presents a high photoresponsivity of 910 mA W–1, a specific detectivity of ∼1.04 × 1011 jones, and a fast response speed of 15.1/18.2 μs under 808 nm irradiation. Furthermore, a stable and reproducible broad-band detection (325–2000 nm) is achieved, due to the efficient NIR light absorption of TaIrTe4. In particular, the device presents impressive responsivities of 14/1.32/0.45 mA W–1 under 1310/1550/2000 nm light, respectively. Notably, these excellent performances of the TaIrTe4/Si nanostructures are superior to those of most of the previously explored 2D materials/Si-based devices and are comparable to those of several commercial silicon photodiode sensors. It is believed that the above results can provide ideas for the research of Weyl semimetals in the application of high-performance nanoscale optoelectronic devices.

Multilayer Graphene/Epitaxial Silicon Near‐Infrared Self‐Quenched Avalanche Photodetectors

“…The heterostructure photodetectors based on Si and other materials are presented as shown in Figure 4f and Table S1 (Supporting Information). [ 33–43 ] Because of the avalanche effect, the nMAG/epi‐Si photodetector exhibits excellent performance when compared with the previous research results, including a low dark current, high responsivity, and detectivity, as well as a fast response time.…”

Two‐Dimensional Van Der Waals Topological Materials: Preparation, Properties, and Device Applications

“…Owing to the Dirac-like gapless surface state and narrow bandgap, 2D vdW TIs are the suitable candidate materials for room-temperature high-performance broadband photodetection (near-infrared, [99,150,340,341,346,347,349,351,353] mid-infr ared, [11,79,344,345] terahertz [343] ). For example, 2D Bi 2 Te 3 /Si-based photodetector possesses the room-temperature ultrabroadband spectral response from ultraviolet (370.6 nm) to terahertz (118 µm) (Figure 17a,b) and good light intensity resolution (Figure 17c).…”

“…[97] Recently, 2D TaIrTe 4 -based vdW heterostructure has been studied in optoelectronics. [98][99][100] For DSM, the Dirac point can be formed by coinciding two Weyl points with opposite chiral positions in the same momentum space. Therefore, the Dirac point is quadruple degeneracy.…”

Alternative Look at Calcium Digermanide CaGe2: A High-Performing Semimetal Transparent Conducting Material for Ge Optoelectronics

“…The modern civil, scientific, and military applications raise new grand challenges for photonic and optoelectronic devices beyond scalability, low energy consumption, and high photoelectric conversion yield, which are axiomatic golden standards. Among them, flexible sensors, multicolor photodetectors (PDs), and their counterpart niche of the selectively blind ones are worthy of special mention. − These application fields are responsible not only for the rapid discovery of novel light-sensitive materials at the cutting edge of the two-dimensional and topological condensed matter − but for an associated breakthrough of the transparent conducting materials (TCMs), − which are essential parts of any optoelectronic device.…”