Cu_2ZnSnS_4薄膜的制备及其光电性质研究

Electrical and Optical Properties of Cu_2ZnSnS_4 Thin Films Prepared by Sulfurization of Metal Multilayer

利用真空蒸镀法在钠钙玻璃上连续蒸镀Cu/Zn/Sn金属前驱体,在氮气保护下,在550℃对前驱体进行硫化,制备出具有类黝锡矿结构的多晶CZTS薄膜.利用X射线衍射仪(XRD)、紫外-可见分光光度计(UV-VIS)、霍尔测量仪对样品进行了晶体结构、光学性质和电学性质表征.讨论了样品中预期成份比Cu/(Zn+Sn)对CZTS薄膜结构及光电特性的影响.结果表明,当Cu/(Zn+Sn)为0.57时,薄膜具有大于104cm-1光吸收系数、禁带宽度约为1.52 eV、较小的电阻率和较高的电子迁移率,适合作为太阳能电池吸收层.

Cu/Zn/Sn metal precursor were deposited by vacuum evaporation on soda lime glass, then the Cu2ZnSnS4 thin films were successfully prepared by sulfurization of the precursors in an electric furnace in the atmosphere of N2 ＋S （gas） for 3 h at the temperature of 550℃. The crystallographic structures of the samples were determined by X--ray diffractometer （XRD）. The electrical and optical properties were analyzed by Hall effect measurements with Van der Pauw method and UV--VIS spectrophotometer. After sulfurization, the stannite quaternary compound Cu2ZnSnS4 （CZTS）thin films were formed. At last, we discuss the dependence of electrical and optical properties of the samples on the expected atomic ratio of the constituents in CZTS thin films. When the ratio of Cu/（Zn＋Sn） in the precursors is 0.57, the CZTS thin film possesses the absorption coefficient more than 10^4 cm^-1 , band gap energy of about 1.52 eV, low electrical resistivity and high mobility, this thin film is suitable to the use as the absorber in thin film solar cells.