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Senior Scientist I: Computational Science

Dr. Peter Graf's research with NREL's Computational Science Center is primarily focused on bringing state-of-the-art applied mathematics to bear on computational problems involving renewable energy. In particular, he has helped develop the methodology and a suite of software tools to apply advanced computing and optimization techniques to problems of material design. He also developed a highly modular drift-diffusion-device simulation tool for organic photovoltaics research. Current research focuses are (1) optimization of electronic structure of alloys and nanostructures, and (2) multi-scale device simulation and optimization in organic photovoltaics.

Dr. Graf graduated Phi Beta Kappa, with distinction, from Stanford University in 1989. After years as a C/C++ programmer, he entered graduate school and in 2003 received his Ph.D. in Mathematics from the University of California at Berkeley. His thesis involved optimization of model reduction for systems of ordinary differential equations, under advisor Alexandre Chorin.

## Education

2003 Ph.D., mathematics, University of California at Berkeley

1989 B.S., symbolic systems (a combination of Philosophy, Psychology, Computer Science, and Linguistics), Stanford University.

## Selected Publications

- Kose, M.E.; Graf, P.A.; Kopidakis, N.; Shaheen, S.; Kim, K.; Rumbles, G. (2009). "Exciton Migration in Conjugated Dendrimers: A Joint Experimental and Theoretical Study."
(10:18); pp. 3285-3294.*ChemPhysChem* - Graf, P.A.; Kose, M.E.; Kim, K. (2009). "Numerical Formulation of the Effective Medium Approximation: Illustrative Examples and Application to Organic Semiconductors, in Computational Nanoscience — How to Exploit Synergy between Predictive Simulations and Experiment."
*Mater. Res. Soc. Symp. Proc.*; (1177E); Warrendale, Pennsylvania. - Graf, P.A.; Jones, W.B.; Kim, K. (2009). "A Note on the Virtual Crystal Approach to Alloy Optimization."
(228:12); pp. 4309-4311.*Journal of Computational Physics* - Piquini, P.; Graf, P.A.; Zunger, A. (2008). "Band-gap Design of Quaternary (In,Ga)(As,Sb) Semiconductors Via the Inverse-band-structure Approach."
(100); p. 186403.*Phys. Rev. Lett.* - Graf, P.A.; Jones, W.B. (2007). "A Projection-based Multiscale Optimization Method for Eigenvalue Problems."
(39); pp. 235-245.*Journal of Global Optimization* - Kim, K.; Graf, P.A.; Jones, W.B. (2005). "A Genetic Algorithm Based Inverse Band Structure Method for Semiconductor Alloys."
(208:2); pp. 735-760.*Journal of Computational Physics*