He was previously a research scientist at Lawrence Berkeley National Laboratory and University of California – Berkeley. Dr. Chen has published 40 peer-reviewed scientific articles with more than 6,000 citations, holds three U.S. and international patents, is the chair for Materials Research Society Spring Meeting: Titanium Dioxide Nanomaterials in 2011 and 2012, and is a reviewer for many scientific journals, including Science, Journal of the American Chemical Society, and Advanced Materials.