Design,Preparation And Properties Of The Graphene-oxide-based Composite Hole Injection Layer

The hole injection material with high carrier mobility,high visible light transmittance and high chemical stability is mainly used in organic optoelectronic devices such as organic light-emitting devices and organic solar cells.It plays an important role for reducing hole injection barrier,anode modification and blocking electrons to the anode diffusion.The poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate)(PEDOT:PSS)is the most common hole injection material.However,PEDOT:PSS would degrade device performance because of the strong acid and water-absorbing,which could corrode the anode.As a new type of two-dimensional material,graphene oxide(GO)has the great potential for hole injection layer of organic optoelectronic devices.However,there still are some problems for GO,such as the energy level mismatching,poor film-forming property and large roughness.In this thesis,the water-soluble copper phthalocyanine(TSCuPc)and GO composite hole injection layer was designed to meet the energy level matching,block electrons and reduce the anode roughness.Around the design and preparation,properties and application of the composite hole injection layer,the specific work of this paper is as follows:(1)According to the performance requirements of the composite hole injection layer,the GO/TSCuPc composite hole injection layer was designed and a reasonable experimental scheme was developed.The composite hole injection layer was prepared according to the scheme.(2)The roughness,transmittance,and ?-? interaction of GO/TSCuPc composite hole injection layer was studied.The results showed that when the GO solution concentration was 1mg/m L and the TSCuPc rotation speed was above 1000 rpm,the composite film had good uniformity,high transmittance and low roughness to meet the application requirements of organic optoelectronic devices.The?-? interaction between the two molecules increased with the increasing of the layer of number of GO films or the thickness of TSCuPc film.(3)According to the carrier injection and transport model of Organic Light-Emitting Device(OLED),the injection and transport characteristics of GO/TSCuPc composite hole injection layer were simulated and analyzed by single carrier device,and finally compared with PEDOT:PSS-based devices.The results showed that the influence of the injection characteristic was mainly GO film.With the increased of the number of GO layers,the barrier potential difference between the anode and the GO layer increased.While the TSCuPc would influence the transport characteristic.The depth of trap of TSCuPc film decreased with the increasing of the thickness of the TSCuPc film,which is more favorable for the transport of the carrier.(4)OLED devices based on GO/TSCuPc composite hole injection layer were prepared.The characteristics of the emission spectrum,voltage-current density,voltagebrightness and voltage-current efficiency were tested.The results showed that the optoelectronic performance of OLED devices based on GO/TSCuPc composite hole injection layer is better than that based on separate GO and TSCuPc hole injection layer.