Optoelectronic properties of chemical vapor deposition grown monolayer MoS2 nanowires

Monolayer (1 L) MoS2 nanowire possesses large amount of exposed edges, resulting in unique physical properties differing to the large size flake. Preparation of high quality 1 L MoS2 nanowire using chemical vapor deposition (CVD) is still challenging to the best of our knowledge. Herein, by employing space-confined CVD method using Mo foil as Mo source, 1 L MoS2 nanowires with width of similar to 70 nm can be deposited on the surface of 1 L MoS2 flake. Tip-enhanced photoluminescence (TEPL) measurements indicate different PL peak position and intensity distribution across the nanowires. Photosensitive Kelvin probe force microscopy (KPFM) measurements further reveal that these nanowires exhibit lower Fermi level than the 1 L MoS2 flake, resulting in tunable optosensitive charge transfer under different excitation photon energies form 1.58 eV to 2.33 eV.