Three Students Recognized for Excellence in Solar Energy
The Princeton Institute for the Science and Technology of Materials (PRISM) and the Princeton Environmental Institute are pleased to announce the winners of the 2008 Global Photonic Energy Corporation Edith and Martin B. Stein Solar Energy Innovation Awards. There was one undergraduate award winner and two graduate co-winners this year.
The undergraduate award winner is Peter Curtin of the Dept of Chemistry, advisor Prof. Stefan Bernhard. His work has been in the field of the photogeneration of hydrogen from water. His senior thesis is entitled "Structure-Activity Correlations Among Heteroleptic Iridium (III) Photosensitizers in a Novel Catalytic Water Reducing System." A novel experimental system was used to screen for structure-activity trends among a library of cyclometalated iridium [Ir(C^N)2(N^N)]+ photosensitizers. Based on trends elucidated with the combinatorial library, a more detailed study of diimine ligands (N^N) was carried out. Enhanced stability and six times higher catalytic turnover compared to the parent structure were found, enabling additional insight into the relationship between the ligand architecture and catalytic performance.
The Graduate Award will be split between Ms. Joung Eun Yoo of the Dept. of Chemical Engineering, advisor Prof. Lynn Loo, and Mr. Prashant Mandlik of Electrical Engineering, advisor Prof. Sigurd Wagner.
Ms. Yoo’s research has focused on the design and engineering of conductive polymers, with a
particular focus on water-dispersible forms of polyaniline for thin-film applications, such as thin film transistors, sensors, and organic solar cells. She investigated how synthetic parameters affect conductivity and structure. Her work clearly showed that the template of the underlying polymer acid has a critical effect on the conductivity of the final material. By minimizing defects, the conductivity could be increased by an order of magnitude, yielding the highest values yet reported for polymer-acid templated polyanilines.
Prashant Mandlik has worked on novel environmental barrier coatings for flexible organic 
devices. Organic devices are particularly susceptible to environmental degradation, such as from humidity, etc, and solar cells are exposed to relatively harsh conditions compared to other optoelectronic devices. Conventional thin film coatings have drawbacks of high cost, high deposition temperatures, and/or being ineffective barriers. Prashant invented a most surprising novel thin film barrier coating consisting of only a single layer. The film is deposited by plasma-assisted deposition at room temperature from hexamethyldisiloxane and oxygen. In its optimum state, the layer has part oxide and part silicone polymer characteristics. Despite its simplicity, this material outperforms other far more complex multilayer structures as an environmental permeation barrier, even under severe conditions of elevated temperature and humidity.