AlSb多晶薄膜材料的性能研究

Study on AlSb Polycrystalline Thin Films Material

采用共蒸法制备了新型AlSb多晶薄膜.通过XRF、XRD、Hall测试及电导率温度关系等研究了AlSb多晶薄膜的组分、结构及性能.分析表明,刚沉积的AlSb薄膜为非晶相,在540℃以上退火转变为AlSb相,转变的程度取决于退火的温度及Al、Sb的原子配比,其中NAl∶NSb为47.2∶52.8,580℃退火后的薄膜多晶转变最为明显,结晶度较高;测试结果表明,退火后的AlSb薄膜为p型间接带隙半导体,载流子浓度为1019cm-1,吸收系数为104,而且在升降温阶段电导率发生不可逆变化.这种薄膜用于TCO/CdS/AlSb结构的太阳电池器件中已经得到200mV左右的开路电压.

The structural, optical and electrical properties of AISb 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 a- morphous 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 （Ea） is 0. 132eV. During the temperature decreasing process, Ea 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 ×10^4cm^-1. Open circuit voltage of TCO/CdS/AlSb photovohaic device reaches 200mV.