Quantum corrections to temperature dependent electrical conductivity of ZnO thin films degenerately doped with Si

摘要

ZnO thin films degenerately doped with Si (Si_xZn_(1-x)O) in the concentrations range of ～0.5% to 5.8% were grown by sequential pulsed laser deposition on sapphire substrates at 400 ℃. The temperature dependent resistivity measurements in the range from 300 to 4.2 K revealed negative temperature coefficient of resistivity (TCR) for the 0.5%, 3.8%, and 5.8% doped Si_xZn_(1-x)O films in the entire temperature range. On the contrary, the Si_xZn_(1-x)O films with Si concentrations of 1.0%, 1.7%, and 2.0% showed a transition from negative to positive TCR with increasing temperature. These observations were explained using weak localization based quantum corrections to conductivity.