J. David Cohen *76

David Cohen, professor of physics at the University of Oregon, died Oct. 29, 2012. He was 65.

Cohen graduated from the University of Washington in 1968, and after Army service graduated with a Ph.D. in physics from Princeton in 1976. He next held a postdoctoral position at Illinois, and in 1978 began at Bell Labs on his life’s work: the characterization of defects in semiconductors, especially relating to solar cells.

In 1981 he went to the physics department at the University of Oregon, and spent the rest of his career there. He developed measurement techniques now widely relied upon for characterization of solar cells in research laboratories worldwide. He was also a major contributor to the application of the admittance spectroscopy technique to solar cells.

His work represents one of the cornerstones of understanding defect states in amorphous silicon solar cells. His more recent efforts in the area of chalcogenide solar-cell materials are important as foundations for improving their performance.

Cohen was a dedicated adviser and mentor to his students and is remembered as a humanitarian who cared about others. He is survived by his wife, Carol.

Graduate memorials are prepared by the APGA.