Promises of Main-Group Metal Chalcogenide-Based Broken-Gap van der Waals Heterojunctions for Tunneling Field Effect Transistors

Abstract

Design of nanodevices with low power consumption and high performance is highly desirable. Recently, a band-to-band tunneling field effect transistor (TFET) is developed, which offers an opportunity to overcome the thermal subthreshold limit. In this work, we demonstrate that two-dimensional (2D) main-group metal chalcogenides possess small effective masses and suitable band edge positions, which show potentials for TEFT devices. Then, we take GeS/SnS2-1T and GaTe-2H/SnSe2-1T van der Waals (vdW) heterostructures as examples and investigate their electronic properties under various electric fields. We find that these vdW heterostructures composed of main-group metal chalcogenides can transfer from type-II to type-III band alignment if a positive electric field is applied. In addition, the systems show a negative differential resistance (NDR) effect, which could be further enhanced if we lift the gate voltage. The simulated charge currents could be up to the order of μA, making them promising candidates for future TFET devices. Thus, our work provides a useful guideline for the design of 2D nanodevices for tunneling applications.

2D materials-based nanoscale tunneling field effect transistors: current developments and future prospects

“…Apart from suitable type-2 band alignments, the broken bandgap or type-3 band alignments are also highly suitable for TFET design. In this effect, the vdW-TFETs using GaTe/SnSe 2 , GeSe/SnS 2 , GeSe/SnSe 2 , and GeS/SnS 2 have shown considerable potential owing to their suitable brokengap band alignment and lower effective masses 121,122 . Furthermore, type-1 band alignment with a lower bandgap has also been explored for vdW-TFET design.…”

Two-dimensional van der Waals heterostructures (vdWHs) with band alignment transformation in multi-functional devices

“…In practice, manipulation of the electronic characteristics of nanomaterials and nanodevices is accomplished via the electronic eld. 101 External factors such as in/out-plane strain and external electric elds can also inuence the ideal electrical properties of the vdWHs. 102 From a macro perspective, the procedure of infusing mechanical energy into a system is the procedure of introducing strain to a 2D material.…”

“…Furthermore, a positive electric eld can transform the band alignment from type-II to type-III in the heterostructures composed of main-group metal chalcogenides such as in Ges/SnS 2 . 101 To demonstrate how a multifunctional device may be constructed employing an external electric eld and strain, we studied and examined various examples from the ocean of TMDCs-based heterostructures constructed with another TMDCs monolayer or other 2D materials. We have included a few heterostructures that exhibit multifunctional device behavior.…”

The interlayer coupling modulation of a g-C3N4/WTe2 heterostructure for solar cell applications

“…25,26 Hence, promoting the efficiency of carrier separations in 2D materials is of great interest and importance. 27,28 Constructing van der Waals (vdW) heterostructures with different types of 2D materials stacking in a vertical direction has been proved an accessible approach to tune the properties and performance of 2D materials, [29][30][31][32] which have been proved to be one of the most efficient categories to enhance the performance of TMDs and g-C 3 N 4 . It is noted that heterostructure solar cells, considered as next-generation solar cell technology, have attracted great attention because of their fascinating properties in solar cell application.…”