The Power Law of Phonon-Limited Electron Mobility in the 2-D Electron Gas of AlGaN/GaN Heterostructure

The reduction of electron mobility in AlGaN/GaN heterostructures follows the common power law, but with an unexpectedly high power coefficient. Following the experimental verification of the unusual power-coefficient value by a different measurement method, this brief presents an analysis that identifies the temperature dependence of the effective electron mass as the responsible physical mechanism for this effect. Based on this result, the measured values of electron mobility are used to calculate the effective mass of the electrons in AlGaN/GaN heterostructures over a wide temperature range, from 25 °C to 300 °C.