It is with great sadness that we pass on the news that Wladyslaw (Wladek) Walukiewicz, a leading mind in the field of semiconductor materials, passed away on November 9, 2022.
Wladek received his Ph.D. from the Institute of Physics of the Polish Academy of Sciences in Warsaw, and spent a few years working at the National Magnet Laboratory in Boston and MIT before he joined the Electronic Materials research group at the Lawrence Berkeley National Laboratory (LBNL) in 1984. Wladek worked at LBNL until his retirement in 2020 and served as an Adjunct Professor in the Department of Materials Science and Engineering at the University of California, Berkeley and participated in the Singapore-Berkeley Research Initiative for Sustainable Energy from 2017 until his retirement. Wladek was instrumental in developing universal models of defect behavior in semiconductors in order to bridge our fundamental understanding of materials with device performance. Therein he made several important contributions, including the concept of Fermi level stabilization energy, which explained the amphoteric behavior of native defects and the resultant doping limit of wide-bandgap semiconductors; the band anticrossing model, which explained the extraordinary energy bandgap bowing in dilute semiconductor alloy and inspired the exploration of a new class intermediate band solar cell; narrow bandgap nitrides; defects in ferromagnetic semiconductors; mobility analysis in two-dimensional electron gases; and, in his latest years, defects and electron transport in perovskite semiconductors.
Wladek was a highly respected scientist, a thoughtful collaborator, a caring mentor, a devoted family-man, and an avid skier and runner (having run the equivalent of the circumference of the Earth - and more - in his life). He will be greatly missed.