Technical Feature

Technical Feature

Hybrid Organic–Nanocrystal Solar Cells

Delia J. Milliron, Ilan Gur and A. Paul Alivisatos


Recent results have demonstrated that hybrid photovoltaic cells based on a blend of inorganic nanocrystals and polymers possess significant potential for low-cost, scalable solar power conversion. Colloidal semiconductor nanocrystals, like polymers, are solution processable and chemically synthesized, but possess the advantageous properties of inorganic semiconductors such as a broad spectral absorption range and high carrier mobilities. Significant advances in hybrid solar cells have followed the development of elongated nanocrystal rods and branched nanocrystals, which enable more effective charge transport. The incorporation of these larger nanostructures into polymers has required optimization of blend morphology using solvent mixtures. Future advances will rely on new nanocrystals, such as cadmium telluride tetrapods, that have the potential to enhance light absorption and further improve charge transport. Gains can also be made by incorporating application-specific organic components, including electroactive surfactants which control the physical and electronic interactions between nanocrystals and polymer.


  • nanocrystals;
  • organics;
  • photovoltaics;
  • semiconductors;
  • solar cells.

Delia J. Milliron is pursuing postdoctoral studies at the IBM T.J. Watson Research Center. She holds an AB degree in chemistry with a certificate in materials science from Princeton University. She completed her PhD degree in chemistry at the University of California at Berkeley under A. Paul Alivisatos. Her research has involved next-generation electronic materials such as organic molecular crystals, semiconducting polymers, and inorganic nanocrystals. Her work has thus far included development of new materials, their application in light-emitting diodes, photovoltaic cells, and field-effect transistors, and advancing the understanding of dissimilar material interactions that take place in these devices.

Milliron can be reached by e-mail at

Ilan Gur is a National Science Foundation graduate research fellow and PhD candidate in materials science and engineering at the University of California at Berkeley, where he has also earned BA and MS degrees. His scientific research interests are in the design of novel materials systems and device architectures to enable low-cost photovoltaic energy conversion, with a focus on II–VI semiconductor nanostructures and conjugated organic materials. He was the recipient of the National Defense Science and Engineering Graduate fellowship from the U.S. Department of Defense and the United Nations Industrial Development Organization's international research fellowship.

Gur can be reached by e-mail at

A. Paul Alivisatos is a professor of materials science at the University of California, Berkeley, and director of the Materials Sciences Division. He is also the scientific director of the Molecular Foundry Program at the Lawrence Berkeley National Laboratory (LBNL) and holds a senior scientist appointment at LBNL. In the private sector, Alivisatos is the founder and editor in chief of Nano Letters, and the scientific founder of Quantum Dot Corp. and Nanosys Inc.

Alivisatos' research seeks to understand the synthesis and characterization of semiconductor nanocrystals. He holds a BA degree in chemistry from the University of Chicago and a PhD degree in chemical physics from UC–Berkeley. He held a postdoctoral appointment with Louis Brus at AT&T Bell Laboratories and returned to Berkeley in 1988, where he joined the faculty as an assistant professor of chemistry. He was named associate professor in 1993, and became a full professor of chemistry in 1995. He was also given the honor of being named Chancellor's Professor of Chemistry from 1998 to 2001. In 1999, he was named professor of materials science.

He has received many awards for his contributions to the field of nanotechnology, the most recent being election into the National Academy of Sciences and the American Academy of Arts, and receiving the 2005 ACS Award in Colloid and Surface Chemistry.

Alivisatos can be reached by e-mail at