Deposition of heteroepitaxial layers of topological insulator Bi2Se3 in the trimethylbismuth–isopropylselenide–hydrogen system on the (0001) Al2O3 and (100) GaAs substrates

Abstract

Thin solid layers that are formed upon heating of the gaseous trimethylbismuth–isopropylselenide–hydrogen system on the (0001) Al₂O₃ and singular and vicinal (100) GaAs surfaces are studied. The conditions for deposition of metal Bi and phases of Bi₄Se₃, BiSe, and topological insulator Bi₂Se₃ using the MOCVD method are determined. Pure metastable phase BiSe is obtained for the first time. Bi₂Se₃ films with a thickness of no less than 200 nm, a relatively low volume concentration of 3 ×10¹⁸ cm^–3, and a high mobility of carriers at 300 K (1000 cm² V^–1 s^–1) are fabricated.