Luke O. Nyakiti, MS, Ph.D.

Nyakiti 

Office: PMEC 214

Tel:  (409) 741- 4505

Fax: (409) 741 - 7153

E-mail: nyakitil@tamug.edu

Biography

Luke O. Nyakiti, MS, PhD. is Assistant Professor in the department of Marine Engineering and Technology at Texas A&M University – Galveston Campus. His research interests encompasses basic and applied research that focuses on (1) novel large area (semiconducting) two-dimensional material system for energy and electronic applications, (2) the process-structure and functional-property relationship of homoepitaxial growth of 4H- or 6H-SiC on variously varying off-cut SiC substrate, for crystal defects mitigation (basal plane dislocation, stacking faults) and to increase minority carrier lifetime for high power switching devices utilizing chemical vapor deposition (CVD) systems, (3) high k-dielectrics to improve electronic and optoelectronic properties of electronic devices; (4) nanocrystalline metallic alloys for catalytic and electrode applications; (5) employing Optical, electro-mechanical, Electron microscopy and Spectroscopic Characterization techniques.
He received his B.Ed Science in Physics and Mathematics at Egerton University in 1998, Masters of Science in Physics at Wichita State University in 2004, and his PhD degree in the Department of Mechanical Engineering at Texas Tech University in 2008, where his dissertation research emphasized on synthesis – structure relationship of III-nitrides semiconductor material systems, and use of spectroscopic as well as transmission electron microscopic techniques to characterize the semiconductors. Upon graduating in 2008, he was a Postdoctoral researcher at the department of Mechanical Engineering, where he studied nanocrystalline metallic structures of advanced metallic alloys synthesized by pulsed electrodeposition with improved hardness, strength, corrosion, wear resistant and superplasticity.
From 2010 – 2013, Dr. Nyakiti was awarded ASEE-NRL Postdoctoral Research Fellowship in residence at US Naval Research Laboratory - Washington D.C. where he took lead in synthesis-structural characterization and functional property relationship of two dimensional (Epitaxial Graphene) materials systems and their integration into device nanostructures e.g. Field Effect Transistors. He was also responsible in research efforts designed at developing different approaches of homoepitaxial growth of SiC on SiC substrates to mitigate basal plane dislocations and enhancement of minority carrier lifetimes for robust high-voltage, high-power electronic device applications, that can benefit a variety of platforms eg in the Navy’s aircraft carriers, submarines and prototypical all electric combat vehicles that is of interest to the Marine Corps, Army and the Air Force.
Dr. Nyakiti teaches Mechanics of materials, Fundamentals of metal Fatigue and Failure analysis, Material Science, and Advanced Characterization techniques in Transmission Electron Microscopy. He is an active in several national and international material science and engineering societies, such as Material Research Society (MRS), American Vacuum Society (AVS), American Chemical Society (ACS), American Physical Society (APS) and American Association for the Advancement of Science (AAAS). He has authored and coauthor more than 50 archival refereed scientific Journals, proceedings and a book chapter, he also holds a U.S. patent.

Selected Publication List

Patent Disclosures

—    Reduction of Basal Plane Dislocations in Epitaxial SiC using an in-situ etch process (2013)


Book Chapters


“Formation of Epitaxial Graphene” in Graphene Nanoelectronics - From material to Circuits; D. Kurt Gaskill and Luke O. Nyakiti, (ed) Raghu Murali, Springer, July 2011, Springer; 2012 edition (April 30, 2012), ISBN-10: 1461405475, ISBN-13: 978-1461405474

Selected Refereed Journals Articles

1.    “Chemically-Resolved Interface Structure of Epitaxial Graphene on SiC(0001)”, J. D. Emery, B. Detlefs, H. J. Karmel, L. O. Nyakiti, D. K. Gaskill, M. C. Hersam, J. Zegenhagen, M. J. Bedzyk, Physical Review Letters, Submitted under review
2.    “Nucleation of In-grown Stacking Faults and Dislocation Half-loops in 4H-SiC Epitaxy”, M. Abadier, R. L. Myers-Ward, N. A. Mahadik, R. E. Stahlbush, V. D. Wheeler, L. O. Nyakiti, C. R. Eddy, Jr., D. K. Gaskill, H. Song, T. S. Sudarshan, Y. N. Picard and M. Skowronski, Journal of Applied Physics, accepted for publication
3.    “Epitaxial Growth of Cubic and Hexagonal InN Thin Films via Plasma-Assisted Atomic Layer Epitaxy”, N. Nepal, N. A. Mahadik, L. O. Nyakiti, S. B. Qadri, M. J. Mehl, J. K. Hite, and C. R Eddy, Jr., Crystal Growth & Design, 13 (4), 1485–1490 (2013)
4.    “Detection of polar chemical vapors using epitaxial graphene grown on SiC (0001)”, V. K. Nagareddy, H. K. Chan, S. C. Hernández, V. D. Wheeler, R. L. Myers-Ward, L. O. Nyakiti, C. R. Eddy, Jr., S. G. Walton, J. P. Goss, N. G. Wright, D. K. Gaskill, and A. B. Horsfall, Appl. Phys. Lett. 102, 173103 (2013)
5.    “Epitaxial growth of III-Nitride/graphene Heterostructures for Electronic Devices”, N. Nepal, V. D. Wheeler, T. J. Anderson, F. J. Kub, M. A. Maestro, R. L. Myers-Ward, S. B. Qadri, J. A. Freitas, S. C. Hernandez, L. O. Nyakiti, S. G. Walton, K. Gaskill, C. R. Eddy, Jr. Appl. Phys. Express 6, 061003 (2013)
6.    “Graphene FETs for Zero-Bias Linear Resistive FET Mixers”, J. S. Moon, H.-C. Seo, M. Antcliffe, D. Le, C. McGuire, A. Schmitz, L. O. Nyakiti, D. K. Gaskill, P. M. Campbell, K.-M. Lee, and P. Asbeck, IEEE Electron Device Letters, 34, (3), 465 (2013)
7.    “Competing scanning tunneling microscope tip-interlayer interactions for twisted multilayer graphene on the a-plane SiC surface”, P. Xu, M. L. Ackerman, S. D. Barber, J. K. Schoelz, P. M. Thibado, V. D. Wheeler, L. O. Nyakiti, R. L. Myers-Ward, C. R. Eddy, Jr., and D. K. Gaskill, Surface Science 617, 113-117 (2013).
8.    “Oxygen Functionalised Epitaxial Graphene Sensors for  Enhanced Polar Organic Chemical Vapour Detection”, V.K. Nagareddy, J.P. Goss, N.G. Wright, A.B. Horsfall, S.C. Hernández, V.D. Wheeler, L.O. Nyakiti, R.L. Myers-Ward, C.R. Eddy, Jr., S.G. Walton, D.K. Gaskill, IEEE Sensors, 2012,  10.1109/ICSENS.2012.6411289
9.    “Mode-locked 2-μm wavelength fiber laser using a graphene-saturable absorber”, M. Currie, T.  Anderson, V. Wheeler, L. O. Nyakiti, N. Garces, R. L. Myers-Ward, C. R. Eddy, Jr. F. J. Kub, D. K. Gaskill, Optical Engineering, 57 (7) 076101 (2013)
10.    “Graphene manipulation on 4H-SiC(0001) using scanning tunneling microscopy, P. Xu, M. L. Ackerman, S. D. Barber, J. K. Schoelz, D. Qi, P. M. Thibado, V. D. Wheeler, L. O. Nyakiti, R. L. Myers-Ward, C. R. Eddy, Jr., and D. K. Gaskill Japanese Journal of Applied Physics 52, 035104 (2013).
11.    “Lateral graphene Heterostructure Field –Effect Transistor”, J. S Moon, H. –C Seo, F. Stratan, M. Antcliffe, A. Schmitz, R.S Ross, A.A. Kiselev, V.D. Wheeler, L.O. Nyakiti, D. K. Gaskill, K. –M. Lee, P.M. Asbeck, Electron Device Letters, IEEE 34, (9), 1190-1192, 2013 DOI:10.1109/LED.2013.2270368
12.    “Atomic-scale movement induced in nanoridges by scanning tunneling microscopy on epitaxial graphene grown on 4H-SiC(0001)”, P. Xu, S. D. Barber, J. K. Schoelz, M. L. Ackerman, D. Qi, P. M. Thibado, V. D. Wheeler, L. O. Nyakiti, R. L. Myers-Ward, C. R. Eddy, Jr., and D. K. Gaskill, Journal of Vacuum Science and Technology B 31, 04D101 (2013).
13.    “High Temperature Stability of Oxygen Functionalized Epitaxial Graphene/Metal Contact Interfaces”, V. K. Nagareddy, S. C. Hernández, V. D. Wheeler, L. O. Nyakiti, R. L. Myers-Ward,C. R. Eddy, J. P. Goss, N. G. Wright, S.G. Walton, D. K. Gaskill, A. B. Horsfall, Materials Science Forum, 740 – 742, 145-148 (2013)
14.    “Improved Chemical Detection and Ultra-Fast Recovery Using Oxygen Functionalized Epitaxial Graphene Sensors”, V. K. Nagareddy, H. K. Chan, S. C. Hernández, V. D. Wheeler, L. O. Nyakiti, R. L. Myers-Ward, C. R. Eddy, Jr, J. P. Goss, N. G. Wright, S. G. Walton, D. K. Gaskill, A. B. Horsfall, IEEE SENSORS JOURNAL13, (8), 2810 (2013)
15.    “Fluorine Functionalization of Epitaxial Graphene for Uniform Deposition of Thin High-Kappa Dielectrics”, V. Wheeler, ; N. Garces, L. Nyakiti, R. Myers-Ward, G. Jernigan, J. Culbertson, C. Eddy, D. K Gaskill, Carbon , 50, 2307– 2314 (2012)
16.    “Plasma-Based Chemical Modification of Epitaxial Graphene”, S. G. Walton, S. C. Hernández, M. Baraket, V. D. Wheeler, L. O. Nyakiti, R. L. Myers-Ward, C. R. Eddy, D. K. Gaskill, Materials Science Forum  717 – 720, 657-660 (2012)
17.    “Electrical Characterization of the Graphene-SiC Heterojunction” , T. J. Anderson, K. D. Hobart, L. O. Nyakiti, V.D. Wheeler, R. L. Myers-Ward, J. D. Caldwell, F. J. Bezares, D. K. Gaskill, C.R. Eddy, F. J. Kub, G. G. Jernigan, M.J. Tadjer, E. A. Imhoff,  Materials Science Forum 717 - 720, 641-644 (2012)
18.    “Positive Temperature Coefficient SiC PiN Diodes”, E. A. Imhoff, K. D. Hobart, F. J. Kub, M.G. Ancona, R. L. Myers-Ward, N.Y. Garces, V. D. Wheeler, L.O. Nyakiti, C. R. Eddy, D. K. Gaskill, Materials Science Forum, 717 - 720, 981-984 (2012)
19.    “Secondary electron dopant contrast imaging of compound semiconductor junctions”, S. Chung,  ; V. Wheeler, L.O.  Nyakiti, C.R. Eddy, D.K. Gaskill, M. Skowronski, Y.N. Picard, Journal of Applied Physics , 110, (1), 014902 - 014902-6 (2011)  DOI: 10.1063/1.3597785
20.    “Enabling Graphene based Technologies: Towards Wafer Scale Production of Epitaxial Graphene”, L.O. Nyakiti, V.D. Wheeler, N.Y Garces, R.L. Myers-Ward, C.R. Eddy, Jr., and D.K. Gaskill, Special issue, MRS Bulletin Volume 37, December 2012
21.    “Polarity determination of rough and smooth surface grains in AlN crystals”, L. O. Nyakiti, R. G. Lee, Z. Gu, J. H. Edgar, J. Chaudhuri, Cryst. Res. Technol. 47 (11), 1134–1139 (2012)
22.    “Graphene FET – Based Zero-Bias RF to Millimeter – Wave Detection”, J. Moon, H.-C. Seo, M. Antcliffe, S. Lin, C. McGuire, D. Le, L. O. Nyakiti, D. K. Gaskill, P. M. Campbell, K.-M. Lee, P. Asbeck IEEE Electron Device Letters 33, 10,  1357, 2012
23.    “Investigation of the Epitaxial Graphene/p-SiC Heterojunction”, T.J. Anderson, K.D. Hobart, L.O. Nyakiti, V.D. Wheeler, R.L. Myers-Ward, J.D. Caldwell, F.J. Bezares, D.K. Gaskill, C.R. Eddy, Jr, F.J. Kub, G.G. Jernigan, M.J. Tadjer, and E.A. Imhoff, Submitted to IEEE Electron Device letters 33, 11, 2012
24.    “Electrical Characterization of graphene-SiC Heterojunction”, T.J. Anderson, K.D. Hobart, L.O. Nyakiti, V.D. Wheeler, R.L. Myers-Ward, J.D. Caldwell, F.J. Bezares, D.K. Gaskill, C.R. Eddy, Jr, F.J. Kub, G.G. Jernigan, M.J. Tadjer, and E.A. Imhoff, Material Science Forum 717-720, 641-644 (2012)
25.    “Vertical conduction mechanism of the epitaxial graphene/n-type 4H-SiC heterojunction at cryogenic temperatures”, M. J. Tadjer,T. J. Anderson, K. D. Hobart, L. O. Nyakiti, V. D. Wheeler, R. L. Myers-Ward, D. K. Gaskill, C. R. Eddy, Jr., F. J. Kub, and F. Calle, Applied Physics Letters 100, 193506 (2012).
26.    “Bilayer Graphene Grown on 4H-SiC(0001) Step-Free Mesas”, L.O. Nyakiti, R. L. Myers-Ward, V. D. Wheeler, E. A. Imhoff, F.J. Bezares, H. Chun, J. D. Caldwell, A. L. Friedman, B. R. Matis, J. W. Baldwin, P. M. Campbell, J. C. Culbertson, C. R. Eddy, G. G. Jernigan and D. K. Gaskill, Nano letters, 12 (4), 1749–1756 (2012)
27.    “Fluorine functionalization of epitaxial graphene for uniform deposition of thin high-κ dielectrics”, V. Wheeler, N. Garces, L. Nyakiti, R. Myers-Ward, G. Jernigan, J. Culbertson, C. Eddy Jr., D. K. Gaskill, Carbon, 50, 6, 2307, 2012
28.    “Fabrication of top-gated epitaxial graphene nanoribbon FETs using hydrogen-silsesquioxane”, W.  S. Hwang,  K. Tahy, L. O. Nyakiti, V. D. Wheeler, R. L. Myers-Ward, C. R. Eddy, Jr., D. Kurt Gaskill, H. G. Xing, A. Seabaugh, D. Jena, J. Vac. Sci. Technol. B, 30, 3, 03D104 - 03D104-4 , 2012
29.    “Growth of 4H- and 3C-SiC Epitaxial Layers on 4H-SiC Step-Free Mesas”, R. L. Myers-Ward, L. O. Nyakiti, Jennifer K. Hite, Orest J. Glembocki, Francisco J. Bezares, Joshua D. Caldwell, Gene A. Imhoff, Karl D. Hobart, James C. Culbertson, Yoosuf N. Picard, Virginia D. Wheeler, Charles R. Eddy, Jr. and D. Kurt Gaskill, Materials Science Forum 679-680, 119-122 (2011).
30.    “Bilayer Graphene by Bonding CVD Graphene to Epitaxial Graphene”, G. G. Jernigan, T. J. Anderson, J. T. Robinson, J. D. Caldwell, J. C. Culbertson, M. G. Ancona, V. D. Wheeler, L. O. Nyakiti, R. Myers-Ward, A. L. Davidson, A. L. Friedman, P. M. Campbell, . D. Kurt Gaskill, Journal of Vacuum Science and Technology B, 30 (3) 03D110 (2012)
31.    “Observations on C-face SiC Graphene Growth in Argon”, D.K. Gaskill, J.K. Hite, J.C. Culbertson, G.G. Jernigan, J.L. Tedescso, L.O. Nyakiti, V.D. Wheeler, R.L. Myers-Ward, N.Y. Garces and C.R. Eddy, Jr., Materials Science Forum 679-680, 789-792 (2011).
32.    “Transmission Electron Microscopy study of defects in AlN crystals with rough and smooth surface grains”, L. Nyakiti, J. Chaudhuri, Z. Gu, J. H. Edgar, Journal of Crystal Growth, 312, 3479 (2010).
33.    “Anomalies in Hall-Petch Strengthening for Nanocrystalline Au-Cu Alloys Below 10 nm Grain Size”, A.F. Jankowski and L.O. Nyakiti,  Surface and Coatings Technology 205 1398 (2010)
34.    “Characterization of strain-rate sensitivity and grain boundary structure in nanocrystalline gold-copper alloys”, L. O. Nyakiti, A. Jankowski, Metallurgical and Materials Transactions A, Metallurgical and Materials Transactions A, 41 838 (2010)
35.    “Modeling of the effects of different substrate materials on the residual thermal stresses in the aluminum nitride crystal grown by sublimation”, R. G. Lee, L. Nyakiti, A. Idesman, J. Chaudhuri, J. App. Phys. 105, 033521 (2009).
36.     “High –Resolution Electron Microscopy Characterization of nanocrystalline Grain Boundaries in Gold – Copper Alloys”, L. O. Nyakiti, A. Jankowski, J. Chaudhuri, Thin film Solids, 517, 1182 (2008).
37.    “Growth of GaN Nanowires on Epitaxial GaN”,  D. Aurongzeb, D.Y. Song, G. Kipshidze, B. Yavich, L. Nyakiti, R. Lee,  J. Chaudhuri,  H. Temkin and M. Holtz, J. of Electr. Matrls. 37, 8, 1076 (2008).
38.    “Native oxide and hydroxide and their implications for bulk AlN crystal growth”, J.H. Edgar, L. Du, L. Nyakiti, and J. Chaudhuri, J. Cryst. Growth. 310, 17, 4002– 4006 (2008).
39.    “Thermal oxidation of single crystal aluminum nitride – a high resolution transmission electron microscopy study”, J. Chaudhuri, R.G. Lee, L.O. Nyakiti, Z. Gu, J.H. Edgar, and P. Li, Materials Lett. 62, 16, 2465-2468 (2008).
40.    “Transmission electron microscopy study of defect-selective etched (010) ScN crystals”, J. Chaudhuri, R.G. Lee, L. Nyakiti, J. Armstrong, Z. Gu, J.H. Edgar, and J.G. Wen, Mater. Lett. 62 27 (2008).
41.    “Thermal oxidation of single crystalline aluminum nitride”, J. Chaudhuri, L. Nyakiti, R.G. Lee, Z. Gu, J.H. Edgar, and J.G. Wen, Mater. Charact. 58, 672 (2007).
42.    “Modeling of residual thermal stresses for aluminum nitride crystal growth by sublimation”, R. G. Lee, A. Idesman, L. Nyakiti, and J. Chaudhuri, J. App. Phys . 102, 6, 063525 (2007).
43.    “Molybdenum Nitride nanoparticles - High-Resolution Transmission Electron Microscopy study”, J. Chaudhuri, L. Nyakiti, R. G. Lee, Y. Ma, P. Li, Q. L. Cui, L. H. Shen, Journal of Materials Letters.61 26,4763 (2007).
44.    “Defect selective etching of scandium nitride crystals”, Z. Gu, J.H. Edgar, D.W. Coffey, J. Chaudhuri, L. Nyakiti, R.G. Lee, and J.G. Wen, J. Cryst. Growth, 293, 2, 242 (2006).


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