Mattias Juhl has been at UNSW for over ten years studying photovoltaics. During this time Mattias completed his PhD thesis under the supervision of Professor Thorsten Trupke and Scientia Professor Martin Green. The thesis focused on time and spectrally resolved luminescence characterisation of silicon solar cells. Since finishing his PhD, Mattias has continued at UNSW in a postdoctoral position. During this time he has focused his attention on what is are the material limitations that are preventing solar grade silicon from reaching its potential. Mattias is taking a holistic approach to both to collate data from over 50 years of research to help understand and develop new ways to measure the small concentration of defects we now have in solar grade material. New techniques are of particular interests as the established measurement techniques, e.g., DLTS, FTIR, and lifetime spectroscopy have been able to determine these contaminants.