超晶格光伏效应的温度特性

Temperature Dependence of Photovoltaic Effect in Superlattice

在18～300K 度范围内测量了 GaAs/AlGaAs 超晶格和 Ge_xSi_(1-x)/Si 应变层超晶格在不同温度下的光伏谱。在200K 以下,在 GaAs/AlGaAs 超晶格中观测到6个子带间光跃迁激子峰;在100K 以下,GaAs/AlGaAs 的光伏谱反映了超晶格台阶状态密度分布。在 Ge_xSi_1-x/Si 应变层超晶格中,观测到子带和连续带间的光跃迁。并对两类超晶格的光伏特性进行了比较分析。

The photovoltaic spectra of GaAs/AlGaAs superlattices and Ge_xSi_(1-x)/ Si strained layer superlattices are measured at different temperatures ranging from 18K to 300K.Six exeiton peaks corresponding to optical transitions between sub- bands are observed in GaAs/AlGaAs superlattice at temperatures below 200K,The photovoltaic spectra of GaAs/AlGaAs at temperatures below 100K reflect the step- like distribution of two-dimensional state density in superlattice.ln Ge_xSi_(1-x)/Si strained layer superlattice,the optical transitions between subbands and continuous bands are observed.The photovoltaic characteristics of the two kinds of superlat- rices are compared and analysed.