Temperature dependence of transport characteristics of wurtzite GaN epilayers

We report electrical transport properties of intentionally and unintentiona lly doped wurtzite GaN epilayers within the temperature range of 3 K up to 340 K. Specifically, temperature dependence of the carrier concentration, m obility and resistivity are investigated. Obtained data could only be expla ined on the basis of two-band model, namely, high mobility conduction band and low mobility impurity band. The threshold doping concentration for the dominance of the conduction band electrons is estimated to be about 10(18) cm(-3).