Publications and Presentations

Research articles published in refereed journals

J. Xie, S. Mita, Z. Bryan, W. Guo, L. Hussey, B. Moody, R. Schlesser, R. Kirste, M. Gerhold, R. Collazo, and Z. Sitar, "Lasing and longitudinal cavity modes in photo-pumped deep ultraviolet AlGaN heterostructures," Appl. Phys. Lett. 102, 171102 (2013).

Y. Kumagai, Y. Kubota, T. Nagashima, T. Kinoshita, R. Dalmau, R. Schlesser, B. Moody, J. Xie, H. Murakami, A. Koukitu, and Z. Sitar, "Preparation of a freestanding AlN substrate from a thick AlN layer grown by hydride vapor phase epitaxy on a bulk AlN substrate prepared by physical vapor transport," Applied Physics Express 5, 055504 (2012).

R. Collazo, J. Xie, B.E. Gaddy, Z. Bryan, R. Kirste, M. Hoffmann, R. Dalmau, B. Moody, Y. Kumagai, T. Nagashima, Y. Kubota, T. Kinoshita, A. Koukitu, D.L. Irvine, and Z. Sitar, "On the origin of the 265 nm absorption band in AlN bulk crystals," Appl. Phys. Lett. 100, 191914 (2012).

B. Raghothamachar, R. Dalmau, B. Moody, S. Craft, R. Schlesser, J. Xie, R. Collazo, M. Dudley, and Z. Sitar, "Low defect density bulk AlN substrates for high performance electronics and optoelectronics," Materials Science Forum 717-720, 1287-90 (2012).

R. Dalmau, B. Moody, J. Xie, R. Collazo, and Z. Sitar, "Characterization of dislocation arrays in AlN single crystals grown by PVT," Phys. status solidi A 208 (7), 1545-7 (2011).

S. Mita, R. Collazo, A. Rice, J. Tweedie, J. Xie, R. Dalmau and Z. Sitar, "Impact of Gallium Supersaturation on the Growth of N-polar GaN," Physica Status Solidi c 8 (7-8), 2078-80 (2011).

H. S. Craft, A. L. Rice, R. Collazo, Z. Sitar, and J. P. Maria, "Spectroscopic measurements of the surface stoichiometry of chemical vapor deposited GaN," Appl. Phys. Lett. 98, 082110 (2011).

J. Xie, S. Mita, A. Rice, J. Tweedie, L. Hussey, R. Collazo, and Z. Sitar, "Strain in Si doped GaN and the Fermi level effect," Appl. Phys. Lett. 98, 202101 (2011).

R. Dalmau, B. Moody, R. Schlesser, S. Mita, J. Xie, M. Feneberg, B. Neuschl, K. Thonke, R. Collazo, A. Rice, J. Tweedie, and Z. Sitar, "Growth and characterization of AlN and AlGaN epitaxial films on AlN single crystal substrates," J. Electrochem. Soc., 158(5) (2011) H530-H535.

R. Collazo, S. Mita, J. Xie, A. Rice, J. Tweedie, R. Dalmau, and Z. Sitar, "Progress on n-type doping of AlGaN alloys on AlN single crystal substrates for UV optoelectronic applications," Physica Status Solidi (C), DOI 10.1002/pssc.201000964 (2011).

R. Dalmau, B. Moody, R. Schlesser, S. Mita, J. Xie, M. Feneberg, B. Neuschl, K. Thonke, R. Collazo, A. Rice, J. Tweedie, and Z. Sitar, "Growth and characterization of AlN and AlGaN epitaxial films on AlN single crystal substrates," ECS Transactions, SOTAPOCS 52, 33(13) (2010) 43-54.

A. L. Rice, R. Collazo, J. Tweedie, R. Dalmau, S. Mita, J. Xie, and Z. Sitar, "Surface preparation and homoepitaxial deposition of AlN on (0001)-oriented AlN substrates by metalorganic chemical vapor deposition," J. Appl. Phys. 108, 043510 (2010).

Z.G. Herro, D. Zhuang, R. Schlesser, Z. Sitar, “Growth of AlN single crystalline boules,” J. Crystal Growth, 312, 2519-2521 (2010).

Lu P, Collazo R, Dalmau R, Durkaya G, Dietz N, Raghothamachar B, Dudley M, Sitar Z, “Seeded growth of AlN bulk crystals in m- and c-orientation,” J. Cryst. Growth, 312 (1), 58-63 (2009).

P. Lu, J. H. Edgar, C. Cao, K. Hohn, R. Dalmau, R. Schlesser and Z. Sitar, "Seeded growth of AlN on SiC substrates and defect characterization", J. Cryst. Growth 310, 2464-2470 (2008).

Research articles published in refereed proceedings

M. Buegler, S. Gamage, R. Atalay, J. Wang, I. Senevirathna, R. Kirste, T. Xu, M. Jamil, I. Ferguson, J. Tweedie, R. Collazo, A. Hoffmann, Z. Sitar, and N. Dietz, "Reactor pressure - growth temperature relation for InN epilayers grown by high-pressure CVD," SPIE 7784, doi: 10.1117/12.860952 , paper# 77840F-1-7 (2010).

R. F. Davis, S. M. Bishop, S. Mita, R. Collazo, Z. J. Reitmeier and Z. Sitar," Epitaxial Growth Of Gallium Nitride, AIP Conf. Proc. 916, 520 (2007).

D. Zhuang, Z. G. Herro, X. Li, R. Schlesser and Z. Sitar, "Wet Etching of Bulk AlN Crystals," Mater. Res. Soc. Symp. Proc. 955, 0955-I07-10 (2007).

Invited book chapters

R. Dalmau and Z. Sitar, "AlN bulk crystal growth by physical vapor transport," in Springer Handbook of Crystal Growth, edited by G. Dhanaraj, K. Byrappa, V. Prasad, M. Dudley, p. 821 (Springer Verlag, Berlin, 2010).

D. Ehrentraut, Z. Sitar, "Advances in Bulk Crystal Growth of AlN and GaN," MRS Bull. 34, 259-265 (2009).

R. Dalmau, Z. Sitar, "Sublimation growth of AlN crystals," in Encyclopedia of Materials: Science and Technology Updates, edited by K. H. J. Buschow, R. W. Cahn, M. C. Flemings, B. Ilschner, E. J. Kramer, S. Mahajan, and P. Veyssière (Elsevier, Oxford, 2005).

R. Collazo, R. Schlesser, Z. Sitar, “High field transport in AlN,” GaN-based materials and devices, M.S. Shur, R.F. Davis eds, Special topics in electronics and systems, vol 33, p.p. 155-174, World scientific publishing 2004.