First principles design and band engineering of type-II As2C3/Sc2CF2 van der Waals heterostructure

Sep 29, 2026

Systematic first-principles calculations evaluate the structural, electronic, mechanical, thermal, and optical performance of a two-dimensional As2C3/Sc2CF2 van der Waals heterostructure. All stacking variants retain the semiconducting character of the constituent monolayers, forming a type-II band alignment that promotes efficient charge separation. The heterostructure shows strong mechanical robustness and thermal stability, while optical absorption exhibits pronounced enhancement over a broad spectral range. External electric fields enable tunable electronic and contact behavior, including a field-induced semiconductor-to-metal transition under negative bias and reversible switching between type-II and type-I alignment under positive bias, supporting nanoelectronic and optoelectronic applications.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages9

Reading Time23 min

AccessFree to download

Introduction

Overview of 2D materials and heterostructures

Band alignment control strategies

Background on As2C3 and Sc2CF2

Motivation for As2C3/Sc2CF2 heterostructure

RSC Advances PAPER Cite this: RSC Adv., 2026, 16, 788 Received 7th October 2025 Accepted 8th December 2025 DOI: 10.1039/d5ra07652h[rsc.li/rsc-advances](rsc.li/rsc-advances) First principles design and band engineering of type-II As2C3/Sc2CF2 van der Waals heterostructure Nguyen Xuan Sang, ab Nguyen Q. Cuong *cd and Le Phuong Long e In this work, we systematically investigate the structural, electronic, mechanical, thermal, and optical properties of a two-dimensional (2D) As2C3/Sc2CF2 van der Waals (vdW) heterostructure using ﬁrstprinciples calculations. All stacking conﬁgurations preserve the semiconducting nature of their constituent monolayers with indirect bandgaps and form a type-II band alignment, favorable for eﬃcient charge separation. The As2C3/Sc2CF2 heterostructure exhibits excellent mechanical robustness and thermal stability. Optical absorption spectra reveal a signiﬁcant enhancement across a broad spectral range, with the absorption coeﬃcient reaching up to 3 .5 × 105 cm−1 . Furthermore, the electronic properties and contact behavior of the heterostructure can be eﬀectively tuned by applying an external electric ﬁeld. Notably, a semiconductor-to-metal transition is induced under negative electric ﬁeld, while a reversible switching between type-II and type-I band alignments is achieved under the positive direction. These results underscore the potential of the As2C3/Sc2CF2 heterostructure as a versatile candidate for future nanoelectronic, optoelectronic, and ﬁeld-eﬀect device applications. 1 Introduction Two-dimensional (2D) materials1 have emerged as a signi􀀁cant 􀀁eld of study, largely due to their remarkable electronic and optical characteristics.2 Since the initial isolation of graphene,3 research has expanded to encompass a wide array of 2D materials, including but not limited to transition metal dichalcogenides (TMDs),4 hexagonal boron nitride (h-BN),5 phosphorene,6 and MXenes.7 Among them, 2D heterostructures,8,9 formed by vertically stacking diﬀerent monolayers, oﬀer a promising strategy to tailor physical properties by combining the distinct characteristics of individual components. These van der Waals (vdW) heterostructures have demonstrated remarkable potential in modulating bandgap values and band alignment, both of which are crucial for applications in optoelectronics, photovoltaics, and photocatalysis.10–12 In particular, the band alignment type plays a pivotal role in charge carrier separation and transport, where a type-II (staggered) band alignment facilitates the spatial aAtomic Molecular and Optical Physics Research Group, Institute for Advanced Study in Technology, Ton Duc Thang University, Ho Chi Minh City, Vietnam. E-mail: [nguyenxuansang@tdtu.edu.vn](nguyenxuansang@tdtu.edu.vn) bFaculty of Electrical and Electronics Engineering, Ton Duc Thang University, Ho Chi Minh City, Vietnam cInstitute of Research and Development, Duy Tan University, Da Nang 550000, [Vietnam. E-mail: nguyenquangcuong3@duytan.edu.vn](Vietnam. E-mail: nguyenquangcuong3@duytan.edu.vn) dSchool of Engineering & Technology, Duy Tan University, Da Nang 550000, Vietnam eCenter of Scienti􀀁c Research and Application, Lac Hong University, No. 10 Huynh Van Nghe Str, Tran Bien Ward, Dong Nai Province, [Vietnam. E-mail: phuonglong@lhu.edu](Vietnam. E-mail: phuonglong@lhu.edu). vn separation of photogenerated electron–hole pairs, enhancing device eﬃciency. Recently, a variety of strategies, including external electric 􀀁elds,13,14 mechanical strain,15–17 and interface engineering,18,19 have been employed to control the band alignment in 2Dheterostructures. The ability to tune band positions and transition between diﬀerent alignment types oﬀers exciting opportunities for designing next-generation, tunable nanoelectronic and optoelectronic devices. However, accurate prediction of band alignment requires reliable theoretical investigations into the electronic structures and interfacial interactions of these he

FAQs

What is the main focus of the study on As2C3/Sc2CF2?

The study systematically investigates structural, electronic, mechanical, thermal, and optical properties of the As2C3/Sc2CF2 2D van der Waals heterostructure using first-principles calculations.

How does stacking configuration affect the electronic behavior?

All stacking configurations preserve semiconducting nature and produce type-II band alignment with indirect bandgaps, supporting efficient charge separation.

What role does an external electric field play?

An external electric field effectively tunes electronic and contact behavior: negative field induces a semiconductor-to-metal transition, while positive field enables reversible switching between type-II and type-I band alignments.

Sep 29, 2026

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