| Citation | Professor Cullis is distinguished for his pioneering studies of the microscopic structure and behaviour of semiconducting materials. He provided the first crystallogographic details of the complex impurity-iron silicide precipitation processes in device-silicon, and of the important precipitation processes in device-silicon, and of the important precipitation of elemental arsenic in bulk gallium arsenide. Studies of high speed solidification phenomena in silicon, using Q-switched laser-induced melts, revealed notable evidence of consitutional supercooling and a very large enhancement os substitional dopant solubility. He observed conclusively that amorphous silicon melts by a first-order phase transition and obtained the solidification velocity required to amorphize it. Cullis was the first to demonstrate that quantum-domain crystalline nanostructure exists in porous silicon and can account for highly efficient light emission, under photo-excitation. Most recently, his work on epitaxial growth has shown that strain waves in surface ripples on mismatched semiconductor layers lead to elastic relaxation by a new misfit defect formation mechanism. |