Preparation And Properties Of Metal Oxide Thin Films Of Porous Perovskite Solar Cell Hole Transport Layer

The perovskite photovoltaic device of lead halide attracts great attention due to its superior photovoltaic performance.In perovskite solar cells,planar reverse perovskite has become a research hotspot in recent years.The relatively simple preparation process is the main advantage of planar reverse perovskites.There are many factors affecting the efficiency and stability of planar reverse perovskite solar cells,and the hole transporting materials play a vital role.More and more researchers are interested in metal oxide hole transport materials such as nickel oxide and molybdenum oxide because these hole transport materials have good chemical stability,and devices made with these hole transport materials are highly efficient..However,since metal oxides such as nickel oxide and molybdenum oxide also have some disadvantages,as lower electrical conductivity is weak,which results in a relatively low filling factor and short-circuit current of the perovskite solar device prepared from these materials.In order to improve the performance of planar reverse perovskite solar devices,it is preferred to increase the conductivity of the hole transport layer material.According to the current research,doping modification is one of the most effective ways to improve the conductivity of nickel oxide and molybdenum oxide films.In this paper,nickel oxide and molybdenum oxide thin films were doped by reducing graphene oxide,and a planar reverse perovskite solar cell with graphene-doped molybdenum oxide film as hole transport layer was prepared.The effects of doping on the morphology,optical properties and electrical properties of the nickel oxide film were analyzed.The influences of doped modified molybdenum oxide film on the morphology of perovskite film and perovskite solar cell was also analyzed.We have the following results.First,it was confirmed that the optimum thermal treating temperature for nickel oxide film was 500℃.The results show that the incorporation of reduced graphene oxide does not affect the optical properties of the nickel oxide film.And the transmittance of the nickel oxide film after doping is 73.08%and transmittance of the undoped film is 74.03%.The results also show that the addition of reduced graphene oxide can increase the conductivity of the film,with the square resistance at 500℃reduced by 9.32%,and the interface properties of the film are also improved,which is beneficial to the growthof peroskite layer.Secondly,the optimum annealing temperature of the molybdenum oxide is200℃.The results show that doping does not affect the light transmittance of the film,and the conductivity of the film is improved,and the perovskite layer based on the doped reduced graphene oxide molybdenum oxide（MoOx:RGO）film has better crystal quality,and the film is smoother and has good coverage.The perovskite solar cell with MoO_x:RGO film as a hole transporting layer has a maximum efficiency of18.85%,a short circuit current of 21.03 mA.cm^-2,an open circuit voltage of 1.12 V,and a fill factor of 0.77.Compared with the perovskite solar cells with PEODT:PSS,MoO_x and RGO films as hole transport layers under the same conditions,the perovskite solar devices with MoO_x:RGO film as hole transport layer exhibit higher environmental stability and better battery performance.