Eric A. Schiff

Professor of Physics; Associate Dean of Natural Sciences, Mathematics & Psychology; College of Arts & Sciences


201 Physics Building, Syracuse University, Syracuse, NY 13244-1130 USA
(315) 443-3901; FAX: (315) 443-9103

Contents

Some Personal Information

I was brought up in Los Angeles, California, but I'm not a surfer. I am an Alpine skier; no doubt this fact somehow led to my change of residence from southern California to upstate New York. I attended Caltech, in Pasadena, California, and got my B.S. degree in physics and English literature there in 1971. Then I went to Cornell University in Ithaca, New York to do my physics doctoral work with Albert J. Sievers. I also worked for about a year as a software engineer for the Jarrell-Ash company in Waltham, Massachusetts, programming the first general purpose microprocessor, the Intel 4004. After receiving my Ph.D. in 1979, I spent three postdoctoral years at the University of Chicago. I worked mainly in Hellmut Fritzsche's laboratory there. In 1981 I returned to upstate New York as an assistant professor of physics here at Syracuse University. With the exception of research leaves visiting Innovalight, Inc. (2007), Palo Alto Research Center (1995), and Brown University (1988), I have been at Syracuse University since then. I am now a full professor. From 1997-2003 I served as chair of the Department of Physics, and I’m now serving as Associate Dean of Natural Sciences, Mathematics, & Psychology for The College of Arts & Sciences.

I am married to Nancy R. Mudrick, who is a professor of social work at Syracuse University. We have two children, Nate, now a graduate student in economics, and Evan, who works in the film & television industry.

Teaching Interests

I'm very interested in some work going on with a number of other faculty members on our physics undergraduate degree programs. One of these is the Bachelor of Arts (B. A.) degree program; the idea has been to emphasize communications, computer networking, and writing skills along with a broad knowledge of science and technology. Graduates with this degree would normally be interested in entering the business world directly after getting their bachelor's degrees, or entering non-science graduate programs such as law or business administration. I'm particularly excited about several innovative, upper-division physics courses which several professors have developed to accompany our new ideas about physics degrees. These courses include introductory ones requiring calculus only (PHY 307-"Science and Computers," PHY 312-"Relativity and Cosmology," PHY 317-"Stellar and Interstellar Astrophysics") and slightly more advanced ones requiring both calculus and calculus-based physics (PHY 315-"Biological and Medical Physics" and PHY 351-"Instrumentation in Modern Physics).

 

Recently I’ve also been working on biological physics. In 2004, the biology and physics departments created a new bachelor’s degree, the B. A. in Biophysical Science, which should appeal to students with strong interests in both physics and the life sciences. The curriculum has been designed to provide very good preparation for medical school or other health professions. I’ve also taught PHY 315, Biological Physics, twice, which gave me a chance to think more deeply about the connections between my own research (in semiconductor physics) and biology. You can find out more about the degree programs and courses at the web-site Undergraduate physics degree programs at Syracuse University.

I’ve also worked with several other professors in our Department on an NSF-funded project that built a cosmology exhibit for Syracuse’s Museum of Science & Technology (the MOST); Carl Rosenzweig was the principal investigator. One of the goals of this grant is to inform the public about ongoing research in this area. In addition to members of the physics department, the project team included staff members from the MOST, students and faculty from Syracuse University’s Department of Communications Design, as well as teachers and other members of the community.

Several years ago I collaborated with David McNamara and Alan Middleton on creating a JAVA applet to illustrate the vector cross-product; you can access this applet at The Vector Cross-Product: A JAVA Tutorial. The applet has been very well received in its field. It is mirrored in several languages, and has been used millions of times by students.

Research Interests

Amorphous and Nanocrystalline Silicon and Solar Cells

For most of my career as a physicist I have done research on a particular material called amorphous silicon. Crystalline silicon has its atoms arranged in beautiful, regular arrays, and it's the stuff of computer chips and most modern electronics. Amorphous silicon is a non-crystalline version of silicon which is made as a thin-film coating on a substrate; a small variation in the conditions of preparation permit one to make nanocrystalline silicon as well. These thin film semiconductors are very useful for making flat panel displays (used in LCD television sets and laptop computers), solar cells (often seen above emergency call boxes at the side of the road), and sensor arrays (used in modern, digital X-ray machines in hospitals).

Physicists are especially interested in non-crystalline materials because most theories for electrical properties are valid only for crystals; understanding the electrical properties of non-crystalline materials is proving to be very challenging. Electrons in crystalline semiconductors move as if they have mass, and are similar in this regard to ordinary particles moving in a vacuum. This isn't so in non-crystalline semiconductors; one can't find anything analogous to a mass, and instead electron motion often seems to be governed by carriers jumping into and out of slightly defective regions (bandtail traps). There are also many fascinating puzzles associated with the fact that amorphous silicon must be married with hydrogen to make it of much use.

In recent years an important aspect of our research has involved the device physics of amorphous silicon and nanocrystalline silicon based solar cells; many of us working in this field fully expect to live long enough to see solar cells providing a significant fraction of the world's electrical power. For many years our research was supported by subcontracts from the National Renewable Energy Laboratory in Golden, Colorado. We are presently working as a partner on the Solar America Initiative project led by United Solar Ovonic, which is one of the companies that are pioneering thin film solar cells.

Porous Electronic Materials

I have also done some work with two porous electronic materials: porous silicon and porous titania (TiO2). Porous silicon is prepared by etching crystalline silicon. Leigh Canham's 1991 discovery that certain porous silicons luminescence far more efficiently than crystalline silicon spawned a new research specialty on related types of silicon-based optoelectronics which continues to be interest. Our own research explored the fundamental mechanism of electrical transport in porous silicon.

At about the same time as Canham's discovery, Michael Grätzel's group in Switzerland discovered how to make remarkably efficient solar cells based on porous TiO2 (titania). The TiO2 is formed by heating (“sintering”) a powder of the TiO2 nanoparticles, somewhat as one fires clay to make pottery. The resulting porous matrix is stained by a dye, and then filled with a electrolyte. We have published some papers on how electrons move in this type of solar cell. In collaboration with Tewodros Asefa, a professor of chemistry at Syracuse, we have recently started working on a more orderly type of porous titania that is more like a woven fabric than like clay. We think this material could lead to an improvement in the solar conversion efficiency of this type of solar cell, which is presently about 11% at best. It will also be fascinating to find out how diffusion of charge carriers in this form of porous titania compares to diffusion in the sintered material.

Liquid Crystal Cosmology

In addition to this semiconductor work, some years ago I did some research on nematic liquid crystals from the point of view that their "phase transitions" are analogous to the "Kibble mechanism" proposed to explain the large-scale (ie. bigger than galaxies) structure observed in the universe. This work, which was published in 1994 in Science, was a remarkably successful collaboration of an experimenter (myself) with several very creative theorists (Mark Bowick, L. Chandar, and Ajit Srivastava). Both the experimental and theoretical work was carried on very fruitfully by Srivastava (Institute of Physics, Bhubaneswar).

Some publications

A .pdf file with my complete list of publications, as well as links to some reprints, is accessible at http://physics.syr.edu/~schiff/Publications/ . Here's a selection of some of these papers:

 

"Polyaniline on crystalline silicon heterojunction solar cells,” Weining Wang and E. A. Schiff, Appl. Phys. Lett. 91 133504 (2007).

"Hole mobility limit of amorphous silicon solar cells," Jianjun Liang, E. A. Schiff, S. Guha, Baojie Yan, and J. Yang, Appl. Phys. Lett. 88 063512 (2006).

"Hole Drift Mobility Measurements in Microcrystalline Silicon," T. Dylla, F. Finger, and E. A. Schiff, Appl. Phys. Lett. 87, 032103 (2005).

"Drift-mobility measurements and mobility-edges in disordered silicons," E. A. Schiff, J. Phys.: Condens. Matter 16, S5265-5275 (2004).

“Low-mobility Solar Cells: A Device Physics Primer with Application to Amorphous Silicon,” E. A. Schiff, Solar Energy Materials and Solar Cells 78, 567-595 (2003).

"Amorphous Silicon Based Solar Cells," Xunming Deng and Eric A. Schiff, in Handbook of Photovoltaic Science and Engineering, Antonio Luque and Steven Hegedus, editors (John Wiley & Sons, Chichester, 2003), pp. 505 – 565.

"Photocarrier drift-mobility measurements and electron localization in nanoporous silicon,” P. N. Rao, E. A. Schiff, L. Tsybeskov, and P. M. Fauchet, Chemical Physics 284, 129-138 (2002).

"Electroabsorption Measurements and Built-in Potentials in Amorphous Silicon-Germanium Solar Cells," J. H. Lyou, E. A. Schiff, S. Guha, and J. Yang, Appl. Phys. Lett. 78, 1924-1926 (2001).

"Ambipolar Diffusion of Photocarriers in Electrolyte-Filled, Nanoporous TiO2," N. Kopidakis, E. A. Schiff, N-G. Park, J. van de Lagemaat, and A. J. Frank, J. Phys. Chem B104, 3930--3936 (2000).

"Non-Gaussian Transport Measurements and the Einstein Relation in Amorphous Silicon," Qing Gu, E. A. Schiff, S. Grebner, F. Wang, and R. Schwarz, Phys. Rev. Lett. 76, 3196 (1996).

"High-Field Electron-Drift Measurements and the Mobility Edge in Hydrogenated Amorphous Silicon," Qing Gu, E. A. Schiff, J.-B. Chevrier, and B. Equer, Phys. Rev. B 52, 5695 (1995).

"The Cosmological Kibble Mechanism in the Laboratory: String Formation in Liquid Crystals," M. J. Bowick, L. Chandar, E. A. Schiff, and A. M. Srivastava, Science 263, 943 (1994).

"Modulated Electron-Spin-Resonance Measurements and Defect Correlation Energies in Amorphous Silicon," J.-K. Lee and E. A. Schiff, Phys. Rev. Lett. 68, 2972 (1992).

"Hydrogen and Defects in Amorphous Silicon," Sufi Zafar and E. A. Schiff, Phys. Rev. Lett. 66, 1493 (1991).

Lab Alumni

Weining Wang, Ph.D. 2008, University of Arizona, Tucson, AZ.

Jianjun Liang, Ph.D. 2006, Sierra Solar Power, Inc., Sunnyvale, CA.

Rafik Middya, 2000-05, Sunnyvale, CA.

Siddeshwar Rane, M.S. 2005, Luminus Devices, Inc., Woburn, MA.

Kai Zhu, Ph.D. 2003, National Renewable Energy Laboratory, Golden, CO.

Jonghun Lyou, 1998-99, 2002-2003, Korea University, Seoul, S. Korea.

Thorsten Dylla, 2002-2003, Roland Berger Strategy Consultants, Germany.

Quan Yuan, 1998-2001, dPix, Inc., Palo Alto, CA.

Prasanna Rao, Ph.D. 1999, Microstrategy, Inc., Washington, DC.

Nikos Kopidakis, 1998-99, National Renewable Energy Laboratory, Golden, CO.

Lin Jiang, Ph.D. 1998, Sycamore Networks, Inc., Chelmsford, MA.

Qing Gu, Ph. D. 1996, Photonic Controls, LLC, Horseheads, NY.

Reinhard Schwarz, 1994-95, Instituto Superior Técnico, Lisbon, Portugal.

Qi Wang, Ph. D. 1994, National Renewable Energy Laboratory, Golden, CO.

Homer Antoniadis, Ph. D. 1992, InnovaLight, Inc., Santa Clara, CA.

Steven P. Hotaling, M.S. 1992..

Douglas Melcher, B. S. 1992, Paul, Weiss, Rifkin, Wharton and
     Garrison, attorneys-at-law, Washington, D.C..

Alexander Yusim, B. S. 1992, SDL Inc., San Jose.

Sufi Zafar, Ph. D. 1991, IBM Research Laboratories, Yorktown Heights, NY.

Jung-Keun Lee, Ph. D. 1991, Chonbuk National University, Jeonju, Korea.

Michael A. Parker, Ph. D. 1988, Rutgers University, Piscataway.

Kevin A. Conrad, Ph.D. 1988, Briarcliff, NY.

Ranjana Pandya, Ph.D. 1985, New Paltz, NY.

John Ferrario, M.S. 1984, IBM Research Laboratories, Essex Junction, VT.

http://physics.syr.edu/~schiff/

Last updated July 12, 2008.