Electric Conductivity and Hall Effect in Evaporated Cadmium Selenide Films

Abstract

AbstractConductivity and Hall effect were investigated on evaporated CdSe films either non‐treated or annealed at 400 and 700°C. The measurements are performed in the temperature range from −150 to 400°C. In the lower temperature range the mobility of electrons follows an exponential temperature dependence of the form μeff = μ0 exp (– ΔE/kT) typical for polycrystalline films, which is not only determined by scattering mechanisms alone but also by the numbers and properties of potential barriers at the crystallite boundaries. These properties of polycrystalline film structure also explain the dependence of conductivity and mobility on film thickness found in non‐treated CdSe films. In the high temperature range conductivity and electron concentration strongly increase, indicating a self‐activated conductivity mechanism. The conduction electron concentration is determined here by thermal intrinsic disorder of lattice atoms.