Dielectric Constant Measurement near the Metal-Insulator Transition in Al_0.3Ga_0.7As

Abstract

The dielectric constant of Al_0.3Ga_0.7As:Si was measured near the metal-insulator transition (MIT). The effective electron concentration of the system was adjusted by using persistent photoconductivity. The temperature dependence of the dielectric constant is qualitatively explained by the Efros-Shikrovskii model of disordered insulators. The best fitted value of the MIT critical exponent is close to 2.