Complex sentence: The thesis examiners, unsure of the material, passed his thesis to Einstein for evaluation who endorsed his wave--particle duality proposal wholeheartedly; de Broglie was awarded his doctorate.
Split into simpler sentences: The thesis examiners, unsure of the material, passed his thesis to Einstein for evaluation. Einstein endorsed his wave--particle duality proposal wholeheartedly; de Broglie was awarded his doctorate.