Preparation And Application Of Graphene Film In Solar Cells

Graphene is a two-dimensional material in which monolayer carbon atoms are arranged in a hexagonal honeycomb.Because of its unique physical and chemical properties,it has potential applications in various fields and has great research prospects.But because of its different preparation methods,the quality of graphene grown also caused the concern of many researchers.At present,the commonly used method for growing graphene is chemical vapor deposition(CVD).Just because of the low cost,high film forming rate,high quality,and large area growth,it is still an important development direction for the preparation of graphene thin films by CVD in the future.And it is also an important method for the preparation of graphene studied in this paper.In this thesis,firstly the process parameters of graphene grown on copper foil substrate by atmospheric pressure CVD method are studied,which mainly include the effects of growth temperature,substrate purity,the ratio of growth gas,growth time and substrate position on the growth of graphene.And then successively,a graphene film with a maximum light transmittance of 94.61% and a minimum square resistance of 455.8 Ω/□ was grown on a high-purity copper foil substrate though optimizing the growth conditions.In addition,this paper explores a new method for the preparation of graphene.A 500 nm copper-10 nm carbon structure is deposited on a silicon substrate by magnetron sputtering.Using copper-carbon interfacial catalysis in combination with CVD heat treatment,the effect of different temperatures and holding times on the carbon film was analyzed.As a result,large-area discontinuous graphene films are eventually grown on silicon wafers.At the same time,this paper explores the application of graphene in solar cells and successfully completes the preparation of graphene/silicon Schottky heterojunction devices.According to the analysis of the theory of thermionic electron emission,using the Schottky I-V without illumination,the fitting data Rs is about 1 MΩ,the ideal factor n is about 13.7,and the barrier height ΦB is about 1.18 eV.