Electrophoretic Deposition And Properties Of Thin Films Of Solution-processable Layered Crystals

The astonishing properties of 2D materials from its extraordinary electrical and optical properties to its outstanding mechanical properties,have greatly attracted the attention to the semiconductor industry.Electrophoretic deposition seems to be a very promising strategy for obtaining an epitaxial growth of 2D materials,and achieving a well-defined atomic layer control with a high degree of thin film transparency.Here we report a generic methodology to form a scalable 2D materials films regardless of how conductive is the material.Details as follows:(1)a lateral heterostructure film based on 2D Mo S₂ nanosheets and Sn Se nanoparticles is prepared via a facile one-step electrophoretic deposition method from a high quality suspension fabricated via liquid phase expholiation technique under a controlled conditions of temperature.(2)The deposited films are used as photoanodes materials of PEC solar cell.Mo S₂nanosheets are stacked vertically to form a film and Sn Se is deposited to form nanoparticles.Thus,a distinctive grid-like lateral heterostructure film can be found in scanning electron microscope.Heterostructure can improve the performance of PEC solar cell due to accelerate separation of electron-hole pairs and hinder the recombination.A photoelectrochemical solar cell(PEC)based on hybrid Sn Se/Mo S₂ grid-like structure photoanode showed a great energy conversion performances improvement,as it produced a short circuit current density(J_sc)of1.88 m A cm^-2under illumination intensity of 100 m W/cm² and efficiency of 0.41%while PEC based on sole Sn Se and Mo S₂ electrodes possessed J_sc of 0.58 m A cm^-2and 0.997 m A cm^-2 with efficiency of 0.159%and 0.24%respectively.(3)We elucidate the great effect of applying EPD technique to the liquid phase expholiated graphene,hexagonal boron nitride and black phosphorene nanosheets colloidal suspensions for obtaining a continuous and scalable films on ITO/PET substrate with a high degree of transparency and flexibility.FESEM,EDAX elemental mapping,XRD and raman characterization analysis are done for the deposited films.I-V characteristics of Gr/ITO/PET and BP/ITO/PET devices are measured.The linear relationship is referring to the ohmic contact between the deposited thin film and the conductive substrate(ITO/PET).