Effect of Annealing on Al-Sb Multilayer Films

The metallic films of Al and Sb were deposited alternately on quartz glass substrates by magnetron sputtering method and then annealed at hightemperature in vacuum to obtain AlSb polycrystalline. The structural, electrical and optical properties of the films before and after annealing were studied with X-ray diffraction (XRD), Hall effect, the temperature dependence of the dark conductivity and UV-Vis transmission and reflection spectra. XRD results show that AlSb multilayers transform to AlSb polycrystalline cubic phase films with preferred orientation in (111) direction. The measurement results indicate that the annealed AlSb films are Ptype semiconductor with the carrier density of 1019cm-3 and the absorption coefficient is higher than 104cm-1 in the visible light. After annealed at 580℃, the indirect energy band-gap of the AlSb film is about 1.64eV. During the temperature increasing process, the conductivity activation energy Ea is 0.01 and 0.11eV. The open circuit voltage of 107mV is achieved in TCO/CdS/AlSb/ZnTe:Cu/Au devices, which demonstrates the potential of AlSb as the absorber layer in solar cells.