Continuous Laser Of Low Power Density Reduce Graphene Oxide Thin Film

As a new type of nanometer materials,showing unique advantages and popular in electrical,optical,mechanical,magnetic,and many other aspects,graphene becomes a research hotspot in recent years.Graphene mainly are applied in preparation of semiconductor device and photoelectric conversion,energy storage batteries,electrochemical sensors,etc.In these applications,graphene is often required to be band adjustable,properties controllable.And devices requires presence of graphene in thin film.But as a result of single-layer graphene is six-member ring structure,the nature is very stable,it is difficult to adjust bandgap.It can break graphene chemical inertness that first graphite is oxided into graphene oxide and then graphene oxide is reducde into graphene.It is one of the effective ways to adjust bandgap.And graphene need to be made into film in actual application.So photoreduction graphene oxide film has important research value and practical significance.This article using continuous lasers of low power density in different wavelengths as laser sources,according to the principle of photochemical reduction and photothermal reduction,relationship between influence factors of low power density laser and properties of reduction graphene oxide are invesgated.The main research content is as follows:1.Based on mechanism of photochemical reduction GO and photothermal reduction GO,main influence factors of photoreduction GO were analyzed.According to factors affecting analysis,an experiment system of exposure adjustable,power density adjustable,reducing atmosphere tunable was designed.And methods to characterize properties of reduced GO were designed.2.Graphene oxide film has been prepared by spin coating method.Through analysis effect of spin coating parameters on film thickness,graphene oxide thin films with different thickness samples and ITO electrode has been prepared and characterized.3.Using 488 nm wavelength laser,changing power density and illumination time,effect of different exposure to photochemical reduction GO has been carried out.Changing GO film thickness and reducing atmosphere,effect of film thickness and atmosphere to photochemical reduction GO has been carried out.The results show:(1)Under different exposure,the higher power density,the higher reduction degree of RGO sample;(2)Under the same exposure,before reaching the relatively stable state,the lower power density,the higher reduction degree of RGO sample;But after reaching the relatively stable state,the higher power density,the higher reduction degree of RGO sample.(3)The thickness of graphene oxide film(20-110 nm)does not affect sample reduction degree.(4)Sample's reduction degree is higher in air than in vacuum.4.Using 518 nm and 637 nm laser,changing power density and illumination time,effect of power density to photothermal reduction GO has been carried out.Changing GO film thickness,effect of thickness to photothermal reduced GO has been carried out.The results show:(1)There are laser power density thresholds for photothermal reduction of graphene oxide.When laser power density is larger than the smaller threshold,photothermal cycloaddition will occur;When laser power density is larger than the larger threshold,thermal cracking reaction will severe occur;And the higher power density,the higher sample reduction degree.(2)The thickness of graphene oxide film(20-80 nm)does not affect sample reduction degree.