Ramón Collazo

University Faculty Scholar and Professor

Ramón Collazo received his BS in Physics from the University of Puerto Rico, San Juan, and has been involved in the growth and characterization of wide bandgap semiconductor thin films, especially nitrides and diamond, for the past 11 years. He has been particularly involved in developing a process for controlling the polarity in III-nitrides to develop lateral polarity homojunction along with their application to the first lateral p/n junction. Additionally, he has been involved in the development of AlN bulk single crystal substrates, their surface preparation, and further epitaxial thin film deposition for optoelectronics and power device applications. He was awarded the Facundo Bueso Medal for Physics and has authored over 60 publications and given presentations at national and international conferences.

Collazo’s research interests include Optoelectronic/Power Materials and Devices; III-N Wide Bandgap Semiconductors; Polar Materials: Nitrides and Oxides; Optics: Materials Characterization and Nonlinear


High conductivity and low activation energy in p-type AlGaN
Rathkanthiwar, S., Bagheri, P., Khachariya, D., Mita, S., Quiñones-García, C., Guan, Y., … Sitar, Z. (2023), Applied Physics Letters. https://doi.org/10.1063/5.0141863
(Invited, Digital Presentation) Exploring Interfaces and Polarity to Realize Vertical III-Nitride Superjunction Devices
Pavlidis, S., Khachariya, D., Szymanski, D., Reddy, P., Kohn, E., Sitar, Z., & Collazo, R. (2022), ECS Meeting Abstracts. https://doi.org/10.1149/MA2022-01311313mtgabs
The role of Ga supersaturation on facet formation in the epitaxial lateral overgrowth of GaN
Wang, K., Kirste, R., Mita, S., Washiyama, S., Mecouch, W., Reddy, P., … Sitar, Z. (2022), APPLIED PHYSICS LETTERS, 120(3). https://doi.org/10.1063/5.0077628
Crystallographic Tilt in Aluminum Gallium Nitride Epilayers Grown on Miscut Aluminum Nitride Substrates
Rathkanthiwar, S., Graziano, M. B., Tweedie, J., Mita, S., Kirste, R., Collazo, R., & Sitar, Z. (2022, October 25), PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS, Vol. 10. https://doi.org/10.1002/pssr.202200323
Doping and compensation in heavily Mg doped Al-rich AlGaN films
Bagheri, P., Klump, A., Washiyama, S., Breckenridge, M. H., Kim, J. H., Guan, Y., … Sitar, Z. (2022), APPLIED PHYSICS LETTERS, 120(8). https://doi.org/10.1063/5.0082992
GaN lateral polar junction arrays with 3D control of doping by supersaturation modulated growth: A path toward III-nitride superjunctions
Szymanski, D., Khachariya, D., Eldred, T. B., Bagheri, P., Washiyama, S., Chang, A., … Sitar, Z. (2022), JOURNAL OF APPLIED PHYSICS, 131(1). https://doi.org/10.1063/5.0076044
High electron mobility in AlN:Si by point and extended defect management
Bagheri, P., Quinones-Garcia, C., Khachariya, D., Rathkanthiwar, S., Reddy, P., Kirste, R., … Sitar, Z. (2022), JOURNAL OF APPLIED PHYSICS, 132(18). https://doi.org/10.1063/5.0124589
Large-Area, Solar-Blind, Sub-250 nm Detection AlGaN Avalanche Photodiodes Grown on AlN Substrates
Reddy, P., Mecouch, W., Breckenridge, M. H., Khachariya, D., Bagheri, P., Kim, J. H., … Sitar, Z. (2022, March 10), PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS, Vol. 3. https://doi.org/10.1002/pssr.202100619
Low resistivity, p-type, N-Polar GaN achieved by chemical potential control
Rathkanthiwar, S., Szymanski, D., Khachariya, D., Bagheri, P., Kim, J. H., Mita, S., … Sitar, Z. (2022), APPLIED PHYSICS EXPRESS, 15(8). https://doi.org/10.35848/1882-0786/ac8273
On electrical analysis of Al-rich p-AlGaN films for III-nitride UV light emitters
Jadhav, A., Bagheri, P., Klump, A., Khachariya, D., Mita, S., Reddy, P., … Sarkar, B. (2022), SEMICONDUCTOR SCIENCE AND TECHNOLOGY, 37(1). https://doi.org/10.1088/1361-6641/ac3710

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Ramón Collazo