Structural and optical characterization of Sn incorporation in CuInS_2 thin films grown by vacuum evaporation method

摘要

Structural and optical properties of non-doped and Sn-doped CuInS_2 thin films grown by double source thermal evaporation method were studied. Sn deposition time is taken between 0 and 5 min. The films were annealed at 250 deg C for 2 h in vacuum after evaporation. The X-ray diffraction spectra indicated that polycrystalline CuInS_2 films were successfully obtained after annealing and no Sn binary or ternary phases are observed for the Sn time depositions less or equal to 5 min. The Sn-doped samples after annealing have bandgap energy of 1.45 -1.49 eV. Furthermore, we found that the Sn-doped CuInS_2 thin films exhibit N-type conductivity after annealing.