Abstract
Molybdenum disulfide (MoS2) and molybdenum dioxide (MoO2) were successfully synthesized and characterized in this work. The molybdenum disulfide film was deposited by magnetron sputter, and then annealed with sulfur powder at the temperature of 550 °C to improve the absorption coefficient and crystallinity. The morphology and microstructure of the MoS2 film was characterized by scanning electron microscope (SEM) and high resolution transmission electron microscopy (HR-TEM). The crystallinity of MoS2 film was also measured by Grazing Incidence X-ray diffraction spectroscopy (GIXRD). The composition of MoS2 film was measured by X-ray Photoelectron Spectroscopy (XPS). The band-gap and absorption spectra were analyzed using UV-visible optical absorption spectroscopy. This work successfully obtained a MoS2 film with high absorption coefficient (5.5 104 cm-1). The molybdenum dioxide film was grown by two-step chemical vapor deposition. Molybdenum trioxide was synthesized in the first step, and then reacted with sulfur atmosphere in step two. The morphology and microstructure of the MoO2 film was characterized by scanning electron microscope (SEM). The crystallinity of MoO2 film was measured by Grazing Incidence X-ray diffraction spectroscopy (GIXRD). The composition of MoO2 film was measured by X-ray Photoelectron Spectroscopy (XPS). The electric properties of MoO2 film were measured by Hall effect system. The band-gap and absorption spectra were analyzed by using UV-visible optical absorption spectroscopy, Photoluminescence (PL) and Ultraviolet Photoemission Spectrospocy (UPS). This study successfully obtained the molybdenum dioxide with low resistivity (9.54 × 10-4 ), high carrier mobility (2.28 cm2 V-1 s-1), high carrier concentration (4.5 × 1021 cm-3), and high absorption coefficient (5.75 × 104 cm-1).