Large Area MOVPE Growth of Topological Insulator Bi2Te3 Epitaxial Layers on i-Si (111)

Bi₂Te₃ is attracting a renewed interest, due to its topological insulator properties; however, even using advanced physical and chemical deposition techniques, the growth of high-crystal quality layers on substrates allowing its technological employment, such as Si, is very challenging, due to the structural complexity of Bi₂Te₃. In this work, we present the optimized large area growth of topological insulator Bi₂Te₃ epitaxial layers on un-buffered i-Si (111) substrates via Metal-Organic Vapor Phase Epitaxy (MOVPE), which is of crucial importance for future integration into CMOS compatible spintronic devices. We found that the key to maximizing the layer quality requires a balanced control of the reactor pressure (P), growth temperature (T), and growth time (t). Within a proper parameter window, the grown Bi₂Te₃ thin layers are crystalline, stoichiometric, and highly uniform, also at the local scale. They exhibit a rhombohedral crystalline structure, and they are [001] out-of-plane oriented on the i-Si (111) substrate. Low temperature magnetoresistance measurements revealed clear Weak Antilocalization (WAL) effects, demonstrating that the optimized MOVPE - grown Bi₂Te₃ is a topological insulator, hence opening further possibilities for its technology-transfer to innovative devices.