title: Chemical vapor deposition growth of crystalline monolayer MoSe2.
abstract: Recently, two-dimensional layers of transition metal dichalcogenides, such as MoS2, WS2, MoSe2, and WSe2, have attracted much attention for their potential applications in electronic and optoelectronic devices. The selenide analogues of MoS2 and WS2 have smaller band gaps and higher electron mobilities, making them more appropriate for practical devices. However, reports on scalable growth of high quality transition metal diselenide layers and studies of their properties have been limited. Here, we demonstrate the chemical vapor deposition (CVD) growth of uniform MoSe2 monolayers under ambient pressure, resulting in large single crystalline islands. The photoluminescence intensity and peak position indicates a direct band gap of 1.5 eV for the MoSe2 monolayers. A back-gated field effect transistor based on MoSe2 monolayer shows n-type channel behavior with average mobility of 50 cm(2) V(-1) s(-1), a value much higher than the 4-20 cm(2) V(-1) s(-1) reported for vapor phase grown MoS2.
authors.affiliation: Department of Materials Science & NanoEngineering, Rice University , Houston, Texas 77005, United States.
authors.forename: Xingli
authors.initials: X
authors.lastname: Wang
authors.forename: Yongji
authors.initials: Y
authors.lastname: Gong
authors.forename: Gang
authors.initials: G
authors.lastname: Shi
authors.forename: Wai Leong
authors.initials: WL
authors.lastname: Chow
authors.forename: Kunttal
authors.initials: K
authors.lastname: Keyshar
authors.forename: Gonglan
authors.initials: G
authors.lastname: Ye
authors.forename: Robert
authors.initials: R
authors.lastname: Vajtai
authors.forename: Jun
authors.initials: J
authors.lastname: Lou
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.forename: Emilie
authors.initials: E
authors.lastname: Ringe
authors.forename: Beng Kang
authors.initials: BK
authors.lastname: Tay
authors.forename: Pulickel M
authors.initials: PM
authors.lastname: Ajayan