Chia-Hsing Wu
National Chiao Tung University, Republic of China
Title: The study of epitaxial InxSey thin films grown on GaAs(100) and c-plane sapphire by using molecular beam epitaxy
Biography
Biography: Chia-Hsing Wu
Abstract
In this study, hetero-epitaxy of InxSey thin films grown on GaAs(100) and c-plane sapphire substrates by using molecular beam epitaxy were demonstrated. A phase transformation between γ-In2Se3 and InSe were observed as varying In/Se vapor pressure ratios. The crystal structure were defined by X-ray diffraction and Raman spectroscopy. The pure γ-In2Se3 with In/Se ratio of 0.67 was achieved on GaAs(100) substrate at 400 ℃. In contract, pure InSe with hexagonal structure were achieved on c-plane sapphire as In/Se ratio near 1.04. In the photoluminescence spectrum (PL) of γ-In2Se3, the free exciton emissions was determined at 2.141 eV. The active energy of γ-In2Se3 was around 45 meV which determined by temperature dependent PL. It implies that the γ-In2Se3 is potentially applied in the opto-electric devices. Hxagonal InSe with layered structure would be promising for 2D semicondutor application.