Abstract
In this research, we used chemical vapor deposition to synthesize monolayer WS2、WSe2.The impact of growth parameters of WS2 and WSe2 was investigated, such as gas flow rate, reducing atmosphere(H2), amount of precursor .The high quality of monolayer WS2 and WSe2 was confirmed by optical microscopy,atomic force microscopy(AFM), photoluminescence (PL) and Raman spectroscopy. The growth mechanism was discussed and proposed. In addition, we report on electronics and optoelectrons properties based on back-gated field-effect transistors. The device of WS2 exhibited a excellent photoresponsivity of 63.8A/W. On the other hand, device of WSe2 is ambipolar, could be turned into either n-type or p-type electrical behavior. Finally, we show that hybrid WS2-WSe2 can be synthesized by chemical vapor deposition. PL of hybrid could be tunable by controlling the amount of precursors.