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Controlled Growth of Bilayer‐MoS 2 Films and MoS 2 ‐Based Field‐Effect Transistor (FET) Performance Optimization
Author(s) -
Fang Mingxu,
Wang Fang,
Han Yemei,
Feng Yulin,
Ren Tianling,
Li Yue,
Tang Dengxuan,
Song Zhitang,
Zhang Kailiang
Publication year - 2018
Publication title -
advanced electronic materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.25
H-Index - 56
ISSN - 2199-160X
DOI - 10.1002/aelm.201700524
Subject(s) - materials science , bilayer , monolayer , optoelectronics , field effect transistor , raman spectroscopy , transistor , contact resistance , nanotechnology , electron mobility , chemical vapor deposition , layer (electronics) , analytical chemistry (journal) , electrical engineering , membrane , optics , chemistry , engineering , voltage , biochemistry , physics , chromatography
Abstract The effect of hydrogen flow on MoS 2 film synthesis via chemical vapor deposition is studied systematically. Large‐sized monolayer‐ and bilayer‐MoS 2 triangles can be synthesized controllably at given temperatures. Optical microscopy, Raman spectroscopy, photoluminescence spectroscopy, and atomic force microscopy are used to characterize the number of layers, purity, and uniformity of the MoS 2 triangle films. Moreover, the back‐gated field‐effect transistors (FETs) based on the monolayer‐ and bilayer‐MoS 2 channels are fabricated using traditional micro‐nanoprocessing technology. Electrical behaviors are investigated and the bilayer‐MoS 2 FETs show preferable performance with high mobility (≈21 cm 2 V −1 s −1 ), on‐current (≈22 µA µm −1 ), and a small degradation in the on/off ratio (1.1 × 10 7 ). Finally, the semiconductive phase MoS 2 (2H‐MoS 2 ) is transformed to a metallic phase (1T‐MoS 2 ) to reduce the resistance in metal‐MoS 2 contact. The FET device with 1T‐MoS 2 contact enhances mobility (≈45 cm 2 V −1 s −1 ) and on‐current (≈50 µA µm −1 ) compared with the 2H‐MoS 2 FETs. This work sheds light on the synthesis of variable‐layer MoS 2 films and paves the way for further development regarding MoS 2 film‐based devices.