Investigation On The Properties Of SB-Doped Cdte Thin Films Prepared By Vacuum Evaporation

By doping to change the nature of CdTe thin films to improve the efficiency of CdTe thin films solar cells, which attracts widespread attention. Pure CdTe thin films and metal Sb-doped CdTe thin films are prepared on glass substrates by vacuum evaporation method. Meanwhile, the prepared thin films are annealed in argon environment. Moreover, the phase structure, surface topography, chemical composition, optical and electrical properties of the prepared thin films are separately studied by X-ray diffraction, Atomic force microscopy, Scanning electron microscopy, Photoelectron spectroscopy, UV-Vis spectrophotometer and Hall Effect System.The experimental results show that the phase structure of CdTe thin films doped with Sb, compared with pure CdTe thin films, is unchanged and all the films are found p-type. Doping Sb in pure CdTe thin films significantly enhance the optical absorption in the NIR region and make the absorption edge of the films shift to longer wavelength. Besides, the band gaps of the thin films decrease from1.505eV to1.442eV with the increasing of Sb in CdTe thin films, which means that the optical absorption range of CdTe thin films can be widened by doping with Sb. And, the electrical properties indicate, the carrier concentration of the doped CdTe thin films grow up to1019/cm2and the resistivity of the thin films drop to10-2-10-3Ω·cm, which helps reduce the series resistance and improve the efficiency of the CdTe thin film solar cells. Finally, the results of chemical composition show that the single-source coevaporation method can also be very good control the proportion of Sb and CdTe.