Fabrication And Investigation Of The Photoelectric Properties Of CuI Films

Cuprous iodide??-CuI?,?-? semiconductor with broad band energy gap,high conductivity and zinc blende structure,is a excellent hole-transporting materials and become the hot topics in the study of experts and scholars due to the great optical and electrical properties.CuI thin films have great potential application value in perovskite solar cells,polymer solar cells,heterojunction solar cells and other fields of solar cells.The paper present the preparation of CuI films by continuous pulling method,chemical vapor deposition,and the studies of the photoelectric properties of heterojunction of CuI films.Firstly,CuI films were prepared by the continuous pulling method on the substrate of conductive glass?ITO?with CuI saturated solution as the raw material.We studied the influence of the number of continuous pulling times?10,20,30?on the morphology and photon electronic properties of CuI film using scanning electron microscope?SEM?,X-ray diffraction?XRD?,spectrophotometer and Hall effect instrument.We found that the CuI film sample deposited by the number of 20 pulling times has the best morphology and photoelectric properties.The surface of the sample is composed by nanoparticle with relatively smooth distribution and size.In addition,we studied the influence of Ag doping on the surface morphology,crystal structure,light absorption and electrical characteristic of CuI thin film.It is found that the crystallinity of the Ag doped CuI film film is much better than the undoped film although the crystal structure of it does not change.Moreover,the light absorption of the Ag doped CuI film had significantly enhanced resulting from the light catalytic role of Ag ions.Secondly,we fabricated CuI films by chemical vapor deposition method on the substrate of silicon?Si?and quartz glass using Ag doped CuI saturated solution as the precursor solution and Ar gas as the transport gas.Also,we explored the influence of the deposition time of 20,40,and 60 mins on the surface morphology structure and photoelectronic properties of the CuI films.It is found that the surface of the CuI film looks smooth,and it is easier to get a large area of film samples,and its photoelectric characteristics also increased with increasing time.with the increase of reaction time,It also discussed the difference between the photovoltaic characteristics of CuI thin film prepared by continuous pulling method and chemical vapor deposition.Through the characterization of experimental data,CuI film by chemical vapor deposition had better photoelectric properties.Finally,CuI/MoS₂ heterojunction was prepared on the substrate of the FTO conductive glass by the method of chemical vapor deposition using doped Ag saturated solution of MoS₂ and CuI as the precursor solution and the argon gas as the carried gas.The light absorption characteristics and electrical properties of the CuI/MoS₂ heterojunction were analyzed under the condition of light and dark.The CuI and MoS₂ film exhibit better crystal structure,large area uniform,good light absorption and electrical properties.The light absorption band of CuI/MoS₂ heterojunction coves almost the whole near ultraviolet,visible light and near infrared wavelengths.It is vey useful to improve the photoelectric response and photovoltaic properties of the heterojunction.CuI/MoS₂ heterojunction shows good rectifying characteristics and photoelectric properties,and high photoelectric response characteristics significantly under light,showing that CuI/MoS₂ heterojunction is suit to making high efficiency optoelectronic devices.