Abstract: The structural, optical and electrical properties of AlSb polycrystalline thin films prepared by in co-evaporation vacuum were studied. The results show that the as-deposited AlSb thin films are amorphous phase. And the samples annealed above 540℃ present polycrystalline phases. The degree of transforming amorphous phase into polycrystalline phases depends on the annealing temperature and stoichiometrical composition. When the ratio of Al to Sb is 47.2∶52.8, the films display more obvious polycrystalline phase after annealing at 580℃. Furthermore, some irreversible changes of the conductivity take place in the annealed films during temperature increasing and decreasing processes. During the temperature increasing process, conductance activation energy (E_a) is 0.132eV. During the temperature decreasing process, E_a is 0.044eV from 200℃ to 270℃ and 0.32eV below 200℃. AlSb polycrystalline thin films are pdoping, indirect band semiconductor with absorption coefficient higher than 8×10⁴cm^-1. Open circuit voltage of TCO/CdS/AlSb photovoltaic device reaches 200mV.

Key words: AlSb, anneal, polycrystalline thin film, co-evaporation