Hydrogenated Borophene as a Promising Two-Dimensional Semiconductor for Nanoscale Field-Effect Transistors: A Computational Study

Abstract

As the lightest two-dimensional (2D) metal, borophene was rarely applied in semiconductor devices. The recently synthesized hydrogenated borophene (B 8 H 4 ) opens up the possibility for 2D boron-based semiconductors. Here, by firstprinciples calculations, we evaluate the potential application of B 8 H 4 in nanoscale field-effect transistors (FETs). We disclose the tunable electronic properties of monolayer B 8 H 4 under strain engineering and the promising electrical performance of B 8 H 4based FETs in the ballistic transport regime. We also reveal that pristine B 8 H 4 -FETs can fulfill the ITRS (International Technology Roadmap for Semiconductors) requirement for high-performance devices with 5 nm channel length in terms of on-current, delay time, and power-delay product. Moreover, 5% biaxial compressive strain can further scale B 8 H 4 -FETs down to 3 nm gate length. This study unveils the potential applications of B 8 H 4 in sub-5 nm FETs and underlines the promising role of boron-based semiconductors in future nanoelectronics.

First-Principles Particle-Swarm Structure Calculations on Metal Substrate Modulated Monolayer to Bilayer Borophene Crystalline Structures toward Nanoelectronics

“…The AIMD calculations (Figure S15) indicate that geometrical structures of δ 3 β 12 , BL-α 5 , and IH-BS remain intact at 500 K, and don’t collapse until the temperature reaches 1000, 2000, and 1500 K, respectively. Therefore, such semiconducting properties and excellent stability make BL-α 5 and IH-BS borophene a promising material for nanoelectronics. ,, Note that trivial imaginary frequencies are observed around the Γ point, partially due to the fairly planar potential surface in the vicinity of their ground state . In particular, the ground state of IH-BS is antiferromagnetic and the spin-charge density is shown in Figure S16, consistent with the studies in literature .…”

“…The allotropic forms of boron, featured with attractive electron delocalization, have gained wide research interest in past decades, including three-dimensional (3D) α- and β-rhombohedral boron bulk, two-dimensional (2D) nanosheet, one-dimensional (1D) nanostructure, and zero-dimensional (0D) clusters. , Among them, 2D borophene, analog to graphene, is particularly intriguing with structural polymorphism , and versatile electronic and magnetic characteristics, including metallicity, semiconductivity, , Dirac fermions, , and superconductivity, exhibiting potential for nanoelectronics applications, such as field effect transistors. ,, Over the past decades, extensive theoretical works have reported the stable structures and possible growth mechanism of monolayer borophene on the metal substrate. − Meanwhile, a series of monolayer borophenes have been synthesized experimentally on multiple metal substrates, such as β 12 and χ 3 sheet on Ag(111), δ 3 on Al(111), χ 6 on Ir(111), β 13 on Cu(100), borophenes with hexagon hole density η of 1/5 on Cu(111), and α 5 (η = 1/12) on Au(111), confirming the substrate-modulated polymorphic structures of monolayer borophene.…”

Geometric, Electronic, and Transport Predictions on Two-Dimensional Semiconducting Silicon with Kagome Lattice: Implications for Nanoscale Field-Effect Transistor Applications

“…Besides, the SS is also impacted by the band gap and effective mass of the channel material. In particular, for the ultrascaled FETs with sub-5 nm channels, smaller band gap and effective mass usually lead to larger leakage currents, which is detrimental to gate controllability. − The values of SS are almost the same along the AD and ZD due to the isotropic hole effective masses of the 2D KL-Si. More details of the I off , I on , I on / I off (on/off ratio), and SS can be found in Table S2 of the Supporting Information.…”

Borophenes: monolayer, bilayer and heterostructures

“…Borophene has attracted widespread attention in the field of two-dimensional (2D) materials since it was first synthesized in 2015. 1 It is a 2D material made entirely of boron atoms, which have important potential applications in electronics, [2][3][4] energy storage, [5][6][7][8] transport, 9 catalysis, [10][11][12] plasmonics, 13,14 superconductivity, [15][16][17][18] sensors, [19][20][21] etc. In addition, the 2D metallic properties, 1,22 such as Dirac Fermions, 23 ideal flexibility and strength, 24 antiferromagnetism 25 and excellent electronic, 26,27 gas-sensing 28 and transport 9 properties of borophene, have also attracted widespread attention from researchers.…”

“…Researchers are also exploring the use of borophene in transistors. Some special borophene phases and hydrogenated borophene exhibit semiconducting properties, 45,46 which make borophene transistors a reality, [2][3][4]29,47,48 and borophene could be utilized to produce faster and more efficient transistors than those currently available. Borophene is also being studied for use in batteries, due to the large surface zone and exceptional conductance making it an ideal material for use in electrodes, which are critical components of batteries and other energy storage devices.…”