Transmuted-Center Fermi-Level Spectroscopy in Slow-Neutron-Irradiated ZnO

Abstract

Measurements of resistivity vs time and temperature between 70° and 300°K were made on an n‐type ZnO crystal which had been irradiated in a slow neutron‐integrated flux of 4.1×10²⁰ cm⁻². During the course of the measurements, the crystal was transmutation doped by the 245‐day half‐life decay of ⁶⁵Zn to ⁶⁵Cu. ⁶⁹Ga was also present in the crystal, as the daughter of the shorter‐lived ⁶⁹Zn. The data were treated using a phenomenological theory of transmuted‐center Fermi‐level spectroscopy (TCFLS) based upon assumptions of sample homogeneity, electron‐system equilibrium, filled transmuted acceptors, and linear relation at constant temperature between Fermi level and log₁₀ resistivity. The data are consistent with a ⁶⁹Ga‐donor model, two levels of which are resolved by the TCFLS technique. The results illustrate the potentiality of TCFLS for determination of semiconductor forbidden‐band state parameters, and also for carrier microscopic‐mobility determination. Two model parameters, corresponding to the concentrations of the shallow forbidden‐band states, were determined to within 3% standard error.