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Optical Characterization and Nanophotonics Laboratory

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Gallium Nitride Characterization

Alumni: Gabriela E. Bunea, Bennett B. Goldberg, William D. Herzog, Gökhan Ulu

 

For material and device characterization, picosecond spectroscopy has a long history of providing valuable scientific understanding of the material system by elucidating the physics of carrier recombination processes. We performed time-resolved photoluminescence measurements to investigate carriers lifetime, nonradiative processes, optical non-linearities in GaN system. We built a microscope capable of less than 100 nm spatial resolution using a SIL. The ability to perform time-resolved measurements with less than 65 ps resolution while maintaining spectral resolution (~ 0.1nm) and spatial resolution (< 100 nm) opens new areas of investigating the local carrier dynamics in semiconductors and devices.

Publications

W. D. Herzog, G. E. Bunea, M. S. Ünlü, B. B. Goldberg, and R. J. Molnar, "Spectroscopy of competing mechanisms generating stimulated emission in gallium nitride," Applied Physics Letters, Vol. 77, No. 25, 18 December 2000, pp. 4145-4147

G. E. Bunea, M. S. Ünlü, and B. B. Goldberg, "Carrier Dynamics Studies of thick GaN Grown by HVPE," Materials Research Society Symposium - Proceedings, Vol. 595, 28-Dec. 3 November 2000, pp. W11.47.1-W11.47.6

G. E. Bunea, G. Ulu, M. S. Ünlü, B. B. Goldberg, and R. J. Molnar, "Photogenerated carrier dynamics in GaN," Pacific Rim Conference on Lasers and Electro-Optics, CLEO - Technical Digest, 7-12 May 2000, pp. 245-246

G. E. Bunea, W. D. Herzog, M. S. Ünlü, B. B. Goldberg, and R. J. Molnar, "Time Resolved Photoluminescence Studies of Free and Donor-Bound Exciton in GaN grown by HVPE," Applied Physics Letters, Vol. 75, No. 6, 9 August 1999, pp. 838-840

W. D. Herzog, T. D. Moustakas, B. B. Goldberg, M. S. Ünlü, R. Singh, and F. P. Dabkowski, "Lasting in Free-Standing GaN Hexagons," Proceedings of CLEO/QELS 1999, May 1999

W. D. Herzog, G. E. Bunea, T. D. Moustakas, M. S. Ünlü, B. B. Goldberg, R. Singh, and F. P. Dabkowski, "Observation of longitudinal laser modes in optically pumped GaN hexagons grown by hydride vapor phase epitaxy," Bulletin of APS centennial meeting, 20-26 March 1999

G. E. Bunea, W. D. Herzog, T. D. Moustakas, M. S. Ünlü, B. B. Goldberg, R. Singh, and F. P. Dabkowski, "Time Resolved Photoluminescence studies of GaN grown by hydride vapor phase epitaxy," Bulletin of APS centennial meeting, 20-26 March 1999

W. D. Herzog, B. B. Goldberg, M. S. Ünlü, R. Singh, and F. P. Dabkowski, "Stimulated Emission from As-grown GaN Hexagons by Selective Area Growth Hydride Vapor Phase Epitaxy," Electronics Letters, Vol. 34, No. 20, October 1998, pp. 1970-1971

W. D. Herzog, R. Singh, T. D. Moustakas, B. B. Goldberg, and M. S. Ünlü, "Photoluminescence Microscopy of InGaN quantum wells," Applied Physics Letters, Vol. 70, No. 11, 17 March 1997, pp. 1333-1335

R. Singh, W. D. Herzog, D. Doppalapudi, M. S. Ünlü, B. B. Goldberg, and T. D. Moustakas, "MBE Growth and Optical Characterization of InGaN/AlGaN Multi-Quantum Wells," Materials Research Society Proceedings Fall 1996, Vol. 449, 2-6 December 1996, pp. 185-190

R. Singh, R. J. Molnar, M. S. Ünlü, and T. D. Moustakas, "Intensity Dependence of Photoluminescence in GaN Thin Films," Applied Physics Letters, Vol. 64, No. 3, January 1994, pp. 336 - 338


Support

NSF CAREER grant no. ECS 9625236 and ARO grant no. DAAG-55-98-1-0143


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