SCANNING PROBE MICROSCOY STUDIES OF POLYCRYSTALLINE SEMICONDUCTORS

This material is based upon work supported by NSF Awards DMR9704780 and DMR0103945

Any opinions, findings and conclusions or recomendations expressed in this material are those of the
     author(s) and do not necessarily reflect the views of the National Science Foundation (NSF).
The goal of this study is an improved understanding of polycrystalline materials through microscopic investigations of individual grains, grain boundaries, and interfaces, and the effects of surface passivation treatments on these properties. The study has focussed on several systems of current interest including polycrystalline GaAs, CdTe, and Cu(In,Ga)Se2. The principal techniques used in this work have been Near-field scanning optical microscopy (NSOM), photocurrent excitation spectroscopy, AFM, and photoluminescence spectroscopy.

Description of  NSOM

Publications:

"Integral Equations Applied to Wave Propagation in Two-Dimensions: Modeling the Tip of a Near-Field Scanning Optical Microscope," C. M. Kelso, P. D. Flammer, J. A. DeSanto, R. T. Collins, JOSA A, 18, 1993 (2001).

"Near Field Scanning Optical Microscopy Cross-Sectional Measurements of Crystalline GaAs Solar Cells," M. K. Herndon, W. C. Bradford, R. T. Collins, B. E. Hawkins, T. F. Kuech, D. J. Friedman and S. R. Kurtz, Appl. Phys. Lett. 77, 100 (2000).

"Direct Patterning of Hydrogenated Amorphous Silicon by Near Field Scanning Optical Microscopy," R. E. Hollingsworth, W. C. Bradford, M. K. Herndon, J. D. Beach and R. T. Collins, submitted Proceedings of the Spring 2000 Meeting of the Materials Research Society.

"Evidence for grain boundary assisted diffusion of sulfur in polycrystalline CdS/CdTe heterojunctions," M. K. Herndon, A. Gupta, V. Kaydanov and R. T. Collins, Appl. Phys. Lett. 75, 3503 (1999).

"Near-Field Scanning Optical Nanolithography using a-Si:H Photoresists," M. K. Herndon, R. T. Collins, R. E. Hollingsworth, P. R. Larson, and M. B. Johnson, Appl. Phys. Lett. 74, 141 (1999).

"Resistless Patterning of Hydrogenated Amorphous Silicon," R. E. Hollingsworth, M. K. Herndon, R. T. Collins, J. D. Benson, J. H. Dinan and J. N. Johnson,  Mat. Res. Soc. Symp. Proc. 557, 821 (1999).

Presentations:

1. "Near-field Microsocpy at the Colorado School of Mines," R. T. Collins, Journee thematique du GdR Optique du Champ Proche, Ecole Centrale Paris, December 20, 2000.

2. "Applications of Near-field Scanning Optical Microscopy," R. T. Collins, University of Northern Iowa Physics Department Colloquium, April 14, 2000.

3. "NSOM Study of Semiconductor Surfaces, Interfaces and Grain Boundaries," R. T. Collins, M. K. Herndon, A. Gupta, V. Kaydanov, T. Ohno, D. J. Friedman, S. R. Kurtz, J. M. Olson, T. F. Kuech, and B. Hawkins, March 2000 Meeting of the American Physical Society, March 20-24, 2000.

4. "Modeling the Electric Field in a Near-Field Scanning Optical Microscope (NSOM)," P. Flammer and C. Kelso,  Spring 2000 Meeting of the Materials Research Society, April 24-28, 2000.

5. "Direct Patterning of Hydrogenated Amorphous Silicon by Near Field Scanning Optical Microscopy," Russell E. Hollingsworth, Mary K. Herndon, William C. Bradford, Joseph D. Beach and Reuben T. Collins, Invited talk, Spring 2000 Meeting of the Materials Research Society, April 24-28, 2000.

6. "Near-field Scanning Optical Microscopy of Semiconductor Surfaces, Interfaces and Grain Boundaries," R. T. Collins, Cielo Communications, Inc., February 17, 2000.

7." Sulfur diffusion in Polycrystalline CdTe, "  R. T. Collins, Presentation to National CdTe Team, NREL, Golden, CO, Oct. 15, 1999.

8. "Resistless Patterning of Hydrogenated Amorphous Silicon Films, R. E. Hollingsworth, M. K. Herndon, R. T. Collins, J. D. Benson, J. H. Dinan, and J. N. Johnson, Oral presentation, 1999 Spring Meeting of the Materials Research Society, Symposium A. April 5-9, 1999.

9.  “Near Field Scanning Optical Microscopy Study of Carrier Recombination at Surfaces and Interfaces,” M. K. Herndon, R. T. Collins, D. J. Friedman , Oral Presentation, 1999 Spring Meeting of the Materials Research Society, Symposium AA. April 5-9, 1999.

10. "Near Field Scanning Optical Nanolithgraphy Using a-Si:H Photoresists," Mary. K. Herndon, Reuben T. Collins, Russell Hollingsworth , poster presentation, 1998 Spring Meeting of the Materials Research Society, Symposium S. April 13-17, 1998

11. "Thin-Film, polycrystalline, photovoltaics," R. T. Collins, Materials Science Colloquium, University of Wisconsin, February 19, 1998.

12. "Near-Field Microscopy,' R. T. Collins, Physics Colloquium, Colorado School of Mines,  November 10, 1998.


last update July 26, 2002