Investigation of noise characteristics of optoelectronic semiconductor materials.

The research is concerned with the characterisation of impact ionisation behaviour in III-V semiconductor alloys. The project will investigate avalanche multiplication and excess noise in the quarternary alloys AlGaInP and AlGaAsSb, using measurements taken on avalanche photodiode structures to infer information about the characteristics of the materials. Of particular interest is the way in which the impact ionisation coefficients change as the composition of the alloy is varied. The end goals of the research are to determine whether materials may be suitable for the development of next generation low noise, high gain-bandwidth product avalanche photodiodes.