Electron-electron interactions in Al_0.15Ga_0.85N/GaN high electron mobility transistor structures grown on Si substrates

We report on magnetotransport studies of Al0.15 Ga0.85 NGaN high electron mobility transistor (HEMT) structures grown on p -type Si (111) substrates. A small but significant decrease of the Hall slope with increasing temperature is observed. Moreover, the converted conductivities reveal that the mobility of the HEMT shows a linear dependence on temperature. All these experimental results can be ascribed to electron-electron interaction (EEI) effects in Alx Ga1-x NGaN HEMT structures grown on Si. The existence of EEI effects can be utilized to design and optimize GaN-based quantum devices on Si such as single-electron transistors and quantum point contacts since EEI effects can strongly modify the transport in semiconductor devices.