• Journal of Semiconductors
  • Vol. 43, Issue 1, 011001 (2022)
DOI: 10.1088/1674-4926/43/1/011001 Cite this Article
. Twist-angle two-dimensional superlattices and their application in (opto)electronics[J]. Journal of Semiconductors, 2022, 43(1): 011001 Copy Citation Text show less

Abstract

Twist-angle two-dimensional systems, such as twisted bilayer graphene, twisted bilayer transition metal dichalcogenides, twisted bilayer phosphorene and their multilayer van der Waals heterostructures, exhibit novel and tunable properties due to the formation of Moiré superlattice and modulated Moiré bands. The review presents a brief venation on the development of “twistronics” and subsequent applications based on band engineering by twisting. Theoretical predictions followed by experimental realization of magic-angle bilayer graphene ignited the flame of investigation on the new freedom degree, twist-angle, to adjust (opto)electrical behaviors. Then, the merging of Dirac cones and the presence of flat bands gave rise to enhanced light-matter interaction and gate-dependent electrical phases, respectively, leading to applications in photodetectors and superconductor electronic devices. At the same time, the increasing amount of theoretical simulation on extended twisted 2D materials like TMDs and BPs called for further experimental verification. Finally, recently discovered properties in twisted bilayer h-BN evidenced h-BN could be an ideal candidate for dielectric and ferroelectric devices. Hence, both the predictions and confirmed properties imply twist-angle two-dimensional superlattice is a group of promising candidates for next-generation (opto)electronics.

1. Introduction

From the successful fabrication of atomically thin carbon films by Andre Geim and Konstantin Novoselov through mechanical exfoliation in 2004[1], graphene not only verified the possibility for stable existence of two-dimensional materials but also exhibited novel and outstanding physical properties including ultra-high carrier mobility[2], ultra-high thermal conductivity[3] and superior mechanical properties[4], which was awarded the Nobel prize in physics 2010. Subsequently, investigations on exploring new 2D materials and their applications have become the frontier fields in condensed physics, such as graphyne[5, 6], two-dimensional transition metal dichalcogenides (TMDs)[7-12], MXenes[13], hexagonal boron nitride (h-BN)[14, 15], black phosphorene (BP)[16, 17], black arsenic[18, 19]. By breaking the weak van der Waals interaction between layers as a “top-down” method like exfoliation or aggregating atoms together as a “bottom-up” method like chemical vapor deposition, researchers have developed variable methods to produce versatile two-dimensional materials and fabricated diverse devices like a field-effect transistor, photodetector and PN diode based on their suitable electronic structures and atomic size along the out-of-plane direction[20-23].

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. Twist-angle two-dimensional superlattices and their application in (opto)electronics[J]. Journal of Semiconductors, 2022, 43(1): 011001
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