As a child, Zhenan Bao remembers spending hours in her mother’s chemistry lab at China’s Nanjing University. “I played, in a safe manner, with squeeze bottles, distilled water, and pH paper,” she recalls. Today, Bao still tinkers with chemistry, but, as one of the world’s foremost experts in organic semiconductors and electronics, she now has considerably more sophisticated toys.
“Her accomplishments span an extraordinary range,” Stanford University chemistry professor Robert M. Waymouth notes, “from illuminating fundamental structure-property relationships in new families of electroactive acenes to the engineering, design, and optimization of sophisticated electronic devices based on semiconducting organic materials.”
Bao, an associate professor of chemical engineering at Stanford, might not seem like a typical recipient of an Arthur C. Cope Scholar Award, which recognizes excellence in organic chemistry. But Bao points out that her work is rooted in organic chemistry. “I apply the fundamentals of organic chemistry to make semiconducting materials,” she explains.
After emigrating from China to the U.S., Bao earned her doctoral degree from the University of Chicago. She then spent eight years working at Lucent Technologies’ Bell Labs, in Murray Hill, N.J., before joining the faculty at Stanford in 2004.
Bao’s myriad accomplishments include discovering the high charge-transport property of regioregular polythiophene. Working with her Bell Labs colleagues, she used the material to demonstrate the first all-printed plastic circuit. She also came up with design rules for organic semiconductors, notably n-type semiconductors.
Bao’s work with dielectric materials is particularly noteworthy—one such material enabled the first demonstration of flexible electronic paper. Another dielectric led to transistors and sensors that work underwater to detect chemicals at parts-per-billion concentrations. Her group recently developed a pressure-sensitive elastic dielectric polymer that could one day lead to medical gloves for doctors that can distinguish healthy cells from cancerous ones.
“Her research evidences great chemical and physical insight, highly creative synthetic and materials processing approaches, incisive implementation of an awesome array of physical techniques, and the highest scientific standards of meticulous execution,” remarks Tobin J. Marks, a chemistry professor at Northwestern University and another 2011 Cope Scholar.
“What is remarkable about her work is the level of innovation and deep scholarship she brings to the challenge of constructing functional organic semiconducting devices, which require knowledge and mastery of the materials chemistry, the processing challenges, and the fabrication of functioning devices,” Waymouth adds.
To other organic chemists who may be looking to enter the materials arena, Bao offers this advice: “In any interdisciplinary work, one needs to learn the language of another discipline, and it may be difficult at the beginning. But if one is persistent and makes the effort, the reward is tremendous. People are, in general, always happy to share their knowledge and take the time to explain things to someone who is willing to learn.”
Bao attributes her success to the many mentors and collaborators she’s had over the years. “I thank them for their support and friendship,” she says, “and I want to do the same for my students and other young scientists.”