准分子激光诱导下 a-Si : H 膜的电导率异常

Conductivity Anomaly of a Si∶H Films under the Induction of Excimer Laser of Low Energy Density

用ＸｅＣｌ准分子激光器对ａ－Ｓｉ∶Ｈ薄膜进行了低能量密度下的辐照处理，测量了激光辐照区内薄膜的电导率随能量密度与脉冲数的变化．研究表明，能量密度在７５ｍＪ／ｃｍ２附近的激光辐照可导致膜的电导率大幅度升高，这种电导率异常是膜表层形成了ｎｍＳｉ晶粒分散于ａ－Ｓｉ∶Ｈ基底中的混合相的反映．

Hydrogenated amorphous silicon (a Si∶H) films have been irradiated by XeCl excimer laser of low energy density. The variations of conductivity in irradiation region with the energy density and the pulse number have been studied. It is shown that the conductivity of a Si∶H films can be increased dramatically when the energy density is in the proximity of 75 mJ/cm 2. Such a conductivity anomaly could be the result of the formation of a mixed phase consisted of Si grains of nanometer level distributed (or scatterred) in the surface layer of the a Si∶H media.