Characterization of Si-doped AlGaN
Nitrides such as GaN and AlGaN are wide-bandgap semiconductors that form the basis for optoelectronics devices emitting in the UV-blue-green spectral range but also high power, high frequency electronic devices. Future applications include radars, base-stations, compact and efficient water purifiers, picoprojectors, solar cells and photoelectrolytic devices for energy harvesting.
The binary compound semiconductor GaN is relatively well known for use in technical applications while the AlGaN-alloy is comparatively unknown. Adding Al to GaN strongly modify the physical parameters of the semiconductor and it is the purpose of this project to investigate the electrical properties including existing literature data.
The aim of this diploma work is to study physical properties of electrical contacts to AlGaN and the electrical conductivity in AlGaN. The material will be grown in our MBE system. The project will be made in close contact to the grower. The structural quality will be probed by X-ray diffraction (XRD) and the surface morphology examined by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Contact will be fabricated in collaboration with existing expertise at Chalmers. The electrical properties of AlGaN will be investigated by Hall-effect measurements were doping levels, resistivity, free electron concentration and mobility will be key parameters to explore. The project is experimental with “hands-on” character and therefore a strong interest and motivation in performing experimental work is required.