Steerable fabrication of MoS2 nanoarray through one-step vacuum thermal evaporation technology

In this work, we investigated the fabrication of intriguing MoS2 nanoarray on poly (ethylene terephthalate) (PET)/Indium tin oxide (ITO) substrates through one-step vacuum thermal evaporation technology. The profiles of MoS2-based nano-bulges were regarded as domed droplets adhered on the substrates. Evaporation rate and thickness were demonstrated to codetermine the morphology of MoS2-based nanoarray. The diameters of MoS2 bulges were determined by the evaporation thickness, while the evaporation rate dominated contact angles between these bulges and ITO films. Besides the nonuniform electrical distribution, a weak van der Waals force in the horizontal direction between MoS2 molecule and jagged ITO film were proposed to be principal factors that influence the morphologies of MoS2. Finally, the field distributions of organic photovoltaic (OPV) devices with MoS2 nanoarray were simulated through finite-difference-time-domain (FDTD). The obvious absorption enhancement effects in FDTD verified the potential application of MoS2-based nanoarray serving as light-coupling layer in OPV devices.