Title : Copper-based hot electrons and high-efficiency I(V) characteristics generated by VSe2 nanodiode
Abstract:
2D materials are growing at a rapid rate driven by the potential extraordinary electronic applications that they can offer. In parallel, terahertz (THz) technologies have continued to receive a great attraction due to the many effective applications, however, it has continuously been hindered due to the low power and wide scale applicability of current THz source technologies. THz surface plasmonics is coming into the forefront as an area which can bridge these two emerging technologies and allow the necessary breakthrough that is needed in the so-called THz source gap region of 0.5 – 3 THz. By utilizing novel 2D materials based on Transition Metal Dichalcogenides (TMDs) with extraordinary electronic, optical, mobility and electrical properties, these limitations breaking results in terms of amplification in THz. Recently 2D vanadium diselenide (VSe2) has gained utmost attention stemming from its outstanding physical-chemical features with high performance applications in energy storage, pharmaceutical and broadband photodetection (visible to terahertz) areas. VSe2 is a typical TMD that exhibits metallic properties with zero band gap due to the strong electron coupling of V4+–V4+. This material shows an extreme electrical conductivity of 106 Sm–1, however, most previous reports are related to the responsivities, band structure and electromagnetic properties, while its optical and electrical properties in THz range are rarely reported. Together with the high level of fabrication technology that has been reached experimentally, computer simulation in nanoscale becomes an indispensable tool for understanding the properties of devices and interfaces that meet ever increasing performance demands. Since, the size of modern electronic and optoelectronic devices continues to scale down, quantum mechanics approaches based on atomistic simulations are inevitable to account for the quantum mechanical phenomena that affect transport and optical properties of nanoscale materials and devices. In the present work, we have developed two kinds of modelling based on materials interfaces and devices as follow: i) The first one concerns materials interfaces linked into a supramolecular architecture in which we calculated the electronic and optical properties of total system using accurate simulation and methodology of the physics involved in THz range. ii) In the second part, self-consistent charge density functional tight-binding (DFTB) calculations have been performed to investigate the electrical properties and transport behavior of the VSe2/Cu nanodevices using different metallic electrodes. The implementation of novel 2D materials for plasmonic amplification of THz sources will be the needed gateway to open-up the current bottle-neck in RF applications beyond 1 THz frequency.
Audience Take Away Notes:
- Develop architectures which can find a solution for surface plasmons couple to the THz radiation
- Efficient nano-scale modelling to amplify THz waves based on surface plasmons in 2D materials
- High effective design of VSe2-based nanodiodes for plasmonic energy conversion
