Abstract

Lateral in-plane heterostructures enable precise control of electronic properties and quantum effects in 2D materials. However, their periodic synthesis is challenging because it requires precise control to maintain sharp, coherent interfaces and compatible growth conditions across different domains. Herein, we report the successful heteroepitaxial growth of Bi₂Te3–Sb₂Te3–Bi₂Te₃ and periodic lateral heterostructures on hexagonal boron nitride (hBN) through in-situ multiple growth steps at different stages using a molecular beam epitaxy (MBE) system. These trilateral heterostructures are fabricated by growing triangular or hexagonal Bi₂Te₃ islands at the very beginning, with typical sizes of several hundred nanometers, on the single-crystalline hBN, followed by the lateral growth of Sb₂Te₃ to form bilateral heterostructures, and finally growing Bi₂Te₃ on the side facets of the bilateral heterostructures. The electron microscopy results confirm the core area as Bi₂Te3, the intermediate layer as Sb₂Te3, and the outermost region as Bi₂Te3. The resulting heterostructures are approximately 4–8 nm thick and several hundred nanometers in lateral dimensions. These heterostructures are found to grow epitaxially on hBN (< ±4° misalignment), and the individual layers are strongly epitaxially aligned with each other. The in-plane heterojunctions are analyzed using the aberration-corrected (Cs-corrected) high-angle annular dark-field scanning transmission electron microscopy technique. We have explored and established the plasmonic properties of these fabricated Bi₂Te3–Sb₂Te3–Bi₂Te₃ lateral heterostructures. In addition, the electronic states and the topological properties of the few quintuple layers (QLs) (2- to 4-QLs) Bi₂Te3–Sb₂Te₃ lateral periodic heterostructures are investigated by first-principles calculations.

Abstract

Lateral in-plane heterostructures enable precise control of electronic properties and quantum effects in 2D materials. However, their periodic synthesis is challenging because it requires precise control to maintain sharp, coherent interfaces and compatible growth conditions across different domains. Herein, we report the successful heteroepitaxial growth of Bi₂Te3–Sb₂Te3–Bi₂Te₃ and periodic lateral heterostructures on hexagonal boron nitride (hBN) through in-situ multiple growth steps at different stages using a molecular beam epitaxy (MBE) system. These trilateral heterostructures are fabricated by growing triangular or hexagonal Bi₂Te₃ islands at the very beginning, with typical sizes of several hundred nanometers, on the single-crystalline hBN, followed by the lateral growth of Sb₂Te₃ to form bilateral heterostructures, and finally growing Bi₂Te₃ on the side facets of the bilateral heterostructures. The electron microscopy results confirm the core area as Bi₂Te3, the intermediate layer as Sb₂Te3, and the outermost region as Bi₂Te3. The resulting heterostructures are approximately 4–8 nm thick and several hundred nanometers in lateral dimensions. These heterostructures are found to grow epitaxially on hBN (< ±4° misalignment), and the individual layers are strongly epitaxially aligned with each other. The in-plane heterojunctions are analyzed using the aberration-corrected (Cs-corrected) high-angle annular dark-field scanning transmission electron microscopy technique. We have explored and established the plasmonic properties of these fabricated Bi₂Te3–Sb₂Te3–Bi₂Te₃ lateral heterostructures. In addition, the electronic states and the topological properties of the few quintuple layers (QLs) (2- to 4-QLs) Bi₂Te3–Sb₂Te₃ lateral periodic heterostructures are investigated by first-principles calculations.

Abstract

Lateral in-plane heterostructures enable precise control of electronic properties and quantum effects in 2D materials. However, their periodic synthesis is challenging because it requires precise control to maintain sharp, coherent interfaces and compatible growth conditions across different domains. Herein, we report the successful heteroepitaxial growth of Bi₂Te3–Sb₂Te3–Bi₂Te₃ and periodic lateral heterostructures on hexagonal boron nitride (hBN) through in-situ multiple growth steps at different stages using a molecular beam epitaxy (MBE) system. These trilateral heterostructures are fabricated by growing triangular or hexagonal Bi₂Te₃ islands at the very beginning, with typical sizes of several hundred nanometers, on the single-crystalline hBN, followed by the lateral growth of Sb₂Te₃ to form bilateral heterostructures, and finally growing Bi₂Te₃ on the side facets of the bilateral heterostructures. The electron microscopy results confirm the core area as Bi₂Te3, the intermediate layer as Sb₂Te3, and the outermost region as Bi₂Te3. The resulting heterostructures are approximately 4–8 nm thick and several hundred nanometers in lateral dimensions. These heterostructures are found to grow epitaxially on hBN (< ±4° misalignment), and the individual layers are strongly epitaxially aligned with each other. The in-plane heterojunctions are analyzed using the aberration-corrected (Cs-corrected) high-angle annular dark-field scanning transmission electron microscopy technique. We have explored and established the plasmonic properties of these fabricated Bi₂Te3–Sb₂Te3–Bi₂Te₃ lateral heterostructures. In addition, the electronic states and the topological properties of the few quintuple layers (QLs) (2- to 4-QLs) Bi₂Te3–Sb₂Te₃ lateral periodic heterostructures are investigated by first-principles calculations.

Abstract

Lateral in-plane heterostructures enable precise control of electronic properties and quantum effects in 2D materials. However, their periodic synthesis is challenging because it requires precise control to maintain sharp, coherent interfaces and compatible growth conditions across different domains. Herein, we report the successful heteroepitaxial growth of Bi₂Te3–Sb₂Te3–Bi₂Te₃ and periodic lateral heterostructures on hexagonal boron nitride (hBN) through in-situ multiple growth steps at different stages using a molecular beam epitaxy (MBE) system. These trilateral heterostructures are fabricated by growing triangular or hexagonal Bi₂Te₃ islands at the very beginning, with typical sizes of several hundred nanometers, on the single-crystalline hBN, followed by the lateral growth of Sb₂Te₃ to form bilateral heterostructures, and finally growing Bi₂Te₃ on the side facets of the bilateral heterostructures. The electron microscopy results confirm the core area as Bi₂Te3, the intermediate layer as Sb₂Te3, and the outermost region as Bi₂Te3. The resulting heterostructures are approximately 4–8 nm thick and several hundred nanometers in lateral dimensions. These heterostructures are found to grow epitaxially on hBN (< ±4° misalignment), and the individual layers are strongly epitaxially aligned with each other. The in-plane heterojunctions are analyzed using the aberration-corrected (Cs-corrected) high-angle annular dark-field scanning transmission electron microscopy technique. We have explored and established the plasmonic properties of these fabricated Bi₂Te3–Sb₂Te3–Bi₂Te₃ lateral heterostructures. In addition, the electronic states and the topological properties of the few quintuple layers (QLs) (2- to 4-QLs) Bi₂Te3–Sb₂Te₃ lateral periodic heterostructures are investigated by first-principles calculations.