Chemical Control of Electronic Structure and Topology in Tellurium-Encapsulated Silicene
Gabriel Elyas Gama Araujo, Andre Luis de Oliveira Batista, Willian Oliveira Santos, Alexandre Amaral Leitao, Alexandre Cavalheiro Dias, Andreia Luisa da Rosa
Abstract
We investigate chemical control of the electronic, optical, and topological properties of two-dimensional Si2X2Te2 (X = B, Al, Ga, and In) monolayers using first-principles calculations. All compounds are dynamically stable semiconductors, with their vibrational and electronic properties evolving systematically upon group-III substitution. Hybrid-functional calculations including spin--orbit coupling reveal predominantly p-orbital band edges and increasingly pronounced relativistic effects from B to In. Most notably, the calculated Z2 invariant identifies Si2In2Te2 as a candidate quantum spin Hall insulator, while the B-, Al-, and Ga-based monolayers remain topologically trivial. Bethe--Salpeter calculations further show that electron--hole interactions redistribute oscillator strength near the absorption onset while preserving a weak in-plane optical anisotropy. Our results establish group-III substitution as a simple chemical route to tune the electronic structure and drive a transition from trivial to nontrivial topology in Si2X2Te2 monolayers.
Create a lesson
Related papers
Divergence between long- and short-wavelength magnon damping in spinel ferrites
Christopher T. Parzyck, Octave Duros, Hari Paudyal et al.
An Atlas and Design Rules for Single- and Dual-Atom Alloys
Fabian Berger, Yicheng Wang, E. Charles H. Sykes et al.
Epitaxial inversion of spontaneous polarization in ε-Ga2O3
Yan Wang, Zhigao Xie, Weihua Tang et al.
Gauge-including neural-network quantum Monte Carlo for molecules in magnetic fields
Chengye Lü, Weizhong Fu, Xin-gao Gong et al.
Photoresponse properties of single-crystalline thick film based on high-entropy topological insulator (Bi3/4Sb1/4)2(Te2/5Se2/5S1/5)3
Alexei Vasilev, Marina Zhezhu, Oleg Ivanov
Adaptive Substrate Support Based on Thin-Film Piezoelectric Actuators
Ertuğ Şimşek, Bas Jansen, Marcelo Ackermann et al.