chris g. van de walle is a professor in the materials department at the university of california, santa barbara. he received a ph.d. in electrical engineering from stanford university in 1986. prior to joining ucsb in 2004, he was a principal scientist at the xerox palo alto research center (parc). his research interests include first-principles calculations for materials, defects and doping in semiconductors and oxides, surfaces and interfaces, and the physics of hydrogen in materials. van de walle is a fellow of the aps, mrs, aaas, avs, and ieee. he is the recipient of a humboldt research award for senior us scientist, the medard w. welch award, and the david adler award from the aps.