The research object of this paper is CdSe semiconductor material,due to the outstanding performance in opticals,electricals,dynamics which are widely optoelectronic devices such as crystal diodes,laser devices and solar cells.As everyone knows,the crystalline structure and morphology of the films are closely related to their optical and electrical properties.the CdSe thin films prepared by vacuum thermal evaporation have some problems such as incomplete crystallization,rough surface and poor quality.Therefore,we choose the reasonable annealing temperature and annealing time to optimize the crystalline properties of the films,so as to prepare high quality CdSe nanocrystalline thin films.CdSe thin films were prepared by the vacuum thermal evaporation on glass substrates.The s X-ray diffraction(XRD),scanning electron microscope(SEM)and atomic force microscope(AFM)results demonstrate,For the film with evaporator current 75 A,all diffraction peaks correspond to(002)reflections without second phase.The surface grains of the sample is in good uniform and regular arrangement with hing surface roughness.For the CdSe film was prepared by thermal evaporation,the good crystalline quality when evaporator current is 75 A.The CdSe fims prepared under the evaporator 75 A were annealed in a vacuum for 2 h,the annealing temperatures are 400 ??450 ??500 ? ?600 ?.Under the condition of the vacuum,effects of the different annealing temperatures on the structure properties and surface morphology of samples were studied.The X-ray diffraction(XRD),Scanning electron microscope(SEM)and Atomic force microscope(AFM)results demonstrate,the CdSe film was prepared by thermal evaporation,the ideal heat treatment conditions are that the annealing temperature is 450 ?.Under the condition of 450 ? annealing temperature,the CdSe films prepared under the current of 75 A were annealed at different holding time.The holding time is set at 1 h,2 h,3 h,4 h and 5 h,respectively.The structure properties and the surface morphology of the films were tested by X-ray diffraction(XRD),scanning electron microscope(SEM)and atomic force microscope(AFM)results show,the CdSe film with good crystalline quality and highly c-axis orientation when holding time is 3 h.Under the same annealing temperature and holding time,the CdSe films prepared under the current of 75 A were annealed at different cooling time.The colding time is set at 2 h,3 h,4 h and 5 h,respectively.The structure properties and the surface morphology of the films were tested by X-ray diffraction(XRD),scanning electron microscope(SEM),atomic force microscope(AFM),X ray photoelectron spectroscopy(XPS)and Auger electron spectroscopy(AES),the results show that that CdSe films with good crystalline quality,high purity,uniform distribution,low roughness,the Cd and Se atoms than stoichiometric very close to the CdSe thin film 1:1.and highly c-axis orientation when cooling time is 4 h.The optimum annealing conditions of CdSe films prepared by vacuum thermal evaporation are as follows: the annealing temperature is 450 ?,the holding time is about h,and the cooling time is about 4 h. |