Investigation On Fabrication And Optoelectronic Properties Of Graphene Grown By CVD

Since the discovery of graphene in 2004,the research boom of scientific research has shifted to a new stage.After the Nobel Prize for physics awarded in 2010,graphene has drawn extensive attention from academia level to industry scale.It has excellent physical properties such as high electron mobility,large specific surface area,and intrinsic tensile strength of 130 GPa make it a promising material in various fields.In recent years,to synthesize a high quality graphene,researchers constantly explore the preparation methods for graphene and study its application in optoelectronic devices.At present,the main preparation methods are:mechanical exfoliation method,epitaxial growth method,oxidation-reduction method and chemical vapor deposition method(CVD).Among these,a high quality and large area of graphene can be prepared by CVD method,which is convenient and easy to operate,low preparation cost,and can realize industrialized production,as a result,it has become the mainstream of the large-scale preparation of high quality graphene method.Due to its excellent photoelectric properties,graphene can be used in solar cells.In recent years,the study of solar cells based on graphene has been deep into.For example,the combination of anti-reflection films and the interface layer,the efficiency of the solar cell has been as high as 15.6%.This paper mainly studied on growth of graphene by CVD method on the platinum(Pt)and copper(Cu)foil substrate,and then its transfer onto n-silicon to make graphene/silicon solar cells,and improve the performance 3times by doping and adding anti-reflection layer.We can also achieve the aim to improve the performance of the solar cell by the oxygen plasma treatment.The main contents are as follows:1.The growth of graphene by CVD on platinum substrate,through the bubbling method,we get the homogeneous continuous samples.By means of optical microscope,we obtained the characterization of the integrity of graphene,the quality and uniformity of graphene were judged by Raman spectrum and imaging.We also studied the optical and electrical properties of graphene by the transmittance and mobility of the graphene grown on such substrate.The graphene grown on platinum is neat,continuous,and of high transmittance.2.The realization of control of the ratio of monolayer by CVD on copper substrate,and study the effect of the different ratio of monolayer on the properties of graphene.Using optical contrast,Raman imaging,we determine the percentage ratio of monolayer;the effect of the existence of bilayer and the thick layer of graphene on optical properties and electrical performance.It is found that,as the ratio of monolayer is different,the transmittance and migration rate are also different.3.By controlling the preparation method,the different factors which may affect the performance of graphene-silicon solar cell were studied,including the presence of a new passivation layer of silica as well as the back gate electrode,which is critical to form a p-n junction and detect the current density and voltage characteristic curve of the battery.PMMA removal way can also affect the performance of the battery to a great extent.Furthermore,by spin coating graphene oxide as a dopant and oxygen plasma treatment can promote the efficiency of graphene-silicon solar cells,raises three times.