Electron transport in wide energy gap semiconductors

• Main Author: Cheekoori, Reddiprasad
• Language: English
• Published: University of British Columbia 2012
• Online Access: http://hdl.handle.net/2429/40421

The dependence of the low-field electron drift mobility on the crystal temperature is determined for a number of wide energy gap semiconductors of interest. The materials considered include gallium nitride, aluminium nitride, indium nitride, and zinc oxide; while indium nitride is not a wide energy gap semiconductor in of itself, alloys of indium nitride with gallium nitride are. For the bulk results, it is found that indium nitride exhibits the highest low-field electron drift mobility while aluminium nitride exhibits the lowest low-field electron drift mobility. This is related to the small effective mass of electrons in indium nitride and the large effective mass of electrons in aluminium nitride. For the case of electrons confined within a two-dimensional electron gas, it is found that the low-field electron drift mobility exceeds that corresponding to the bulk material. This is due to the enhanced screening that electron concentrations exceeding the bulk ionized impurity concentrations level offer, i.e., surplus electrons act to further screen the ionized impurities; in a two-dimensional electron gas, the electron concentrations may far exceed those found in a bulk material. Recommendations for further study are suggested.