Opto-electro-magneto-thermal-functional materials: epitaxial growth and charge-spin-heat transport

We design materials for converting different forms of energy (optical, electronic, thermal) into functions (sensing, energy harvesting, information technology). By using atomic layer-by-layer epitaxial synthesis (plasma-assisted molecular beam epitaxy) we can enginer the compositional profiles within heterstructures of different materials (wide band gap semiconductor alloys, magnetic superlattices) with exquisite crystalline quality. Using spatially-resolved optical spectroscopy, we measure the optical properties (photoluminescence, absorption) as a function of temperature (down to 5 K). Making use of ultrafast (~140 femto-second) laser pulses, we carry out pump-probe measurements with ~1 pico-second resolution to map out the time scale of electronic excitations, as well as magnetic and spin dynamics. We also use focused laser pulses to generate local hot-spots that induce temperature gradients leading to thermoelectric and thermo-spin transport phenomena, including the spin-Seebeck effect.

Recent Publications and Preprints

  • "Spectral measurement of the breakdown limit of β-Ga2O3 and field-dependent dissociation of self-trapped excitons and holes"Md M. Adnan, D. Verma, Z. Xia, N. K. Kalarickal, S. Rajan, R. C. Myers, arXiv:2011.00375 (2020)

  • "Interface-Induced Ferromagnetism in µ-Fe2O3/β-Ga2O3 superlattices", Elline C. Hettiaratchy, John S. Jamison, Binbin Wang, Núria Bagués, Rachel A. Guest, David W. McComb, Roberto C. Myers, J. Vac. Sci. Technol. A (2020)

  • "Deep-recessed β-Ga2O3 delta-doped field effect transistors with in situ epitaxial passivation", Chandan Joishi, Zhanbo Xia, John S Jamison, Shahadat H Sohel, Roberto C Myers, Saurabh Lodha, Siddharth Rajan, IEEE Trans. Electron Devices 67, 4813 (2020)

  • "Molecular beam epitaxy of GaN on 2H–MoS2," C. H. Lee, Y. Zhang, J. M. Johnson, R. Koltun, V. Gambin, J. S. Jamison, R. C. Myers, J. Hwang, & S. Rajan, Appl. Phys. Lett., 117, 123102 (2020)

  • "Local Electric Field Measurement in GaN Diodes by Exciton Franz-Keldysh Photocurrent Spectroscopy", Darpan Verma, Md Mohsinur Rahman Adnan, Mohammad Wahidur Rahman, Siddharth Rajan, and Roberto C. Myers, Appl. Phys. Lett. 116, 202102 (2020)

  • "Long lifetime of thermally-excited magnons in bulk yttrium iron garnet", John S. Jamison, Zihao Yang, Brandon L. Giles, Jack T. Brangham, Guanzhong Wu, P. Chris Hammel, Fengyuan Yang, and Roberto C. Myers, Phys. Rev. B 100, 134402 (2019)

  • "Excimer-Mediated Intermolecular Charge Transfer in Self-Assembled Donor–Acceptor Dyes on Metal Oxides", Yongze Yu, Szu-Chia Chien, Jiaonan Sun, Elline C. Hettiaratchy, Roberto C. Myers, Li-Chiang Lin, and Yiying Wu, J. Am. Chem. Soc. 141, 8727-8731 (2019)

  • "Enhanced uniformity of III-nitride nanowire arrays on bulk metallic glass and nanocrystalline substrates", Brelon J. May, Elline C. Hettiaratchy, Camelia Selcu, Binbin Wang, Bryan D. Esser, David W. McComb, and Roberto C. Myers, J. Vac. Sci. Technol. B 37, 031212 (2019)

  • "Controlled Nucleation of Monolayer MoSe2 Islands on Si (111) by MBE", Brelon J. May, Elline C. Hettiaratchy, Roberto C. Myers, J. Vac. Sci. Technol. B 37, 021211 (2019)

  • "Ferromagnetic Epitaxial μ-Fe2O3 on β-Ga2O3: A New Monoclinic form of Fe2O3", John S. Jamison, Brelon J. May, Julia I. Deitz, Szu-Chia Chien, David W. McComb, Tyler J. Grassman, Wolfgang Windl, and Roberto C. Myers, Cryst. Growth Des. 19, 4205-4211 (2019)

Recent News

April 9, 2020

Congratulations to Dr. John Jamison for passing his PhD defense exam!

August 11, 2019

Welcome to Md Mohsinur Rahman Adnan who joined the group as a graduate student in Electrical and Computer Engineering.

February 14, 2019

UV LED microscopy. Video of 320 nm ultraviolet emitting AlGaN nanowire LEDs. Current spreading fingers are 10 microns.

January 9, 2019

Welcome to Darpan Verma who joined the group as a graduate student in Materials Science and Engineering.

November 30, 2018

Congratulations to Dr. Brelon May for passing his PhD defense exam!

October 3, 2018

Brelon May wins another Outstanding Student Paper Award at the North American Molecular Beam Epitaxy (NAMBE) conference!

May 16, 2018

Brelon May wins the Three Minute Thesis (3MT) competition. See his winning presentation below:

April 26, 2018

Myers awarded Harrison Faculty Award for Excellence in Engineering Education. For innovations in materials synthesis and design leading to breakthrough discoveries in spin-based electronics, spin/thermal effects and polarization engineered nanowire heterostructures.

November 27, 2017

Brelion May was awarded a Presidential Fellowship, which is the most prestigious fellowship given by the Graduate School at OSU, recognizing outstanding scholarship and research ability.

October 26, 2017

Brelon May won outstanding student paper award at the North American Molecular Beam Epitaxy Conference (NAMBE).

July 26, 2017

Welcome to Elline Hettiaratchy who joined the group as a graduate student in Materials Science and Engineering.

July 25, 2017

Congratulations to Dr. Zihao Yang for passing his PhD defense exam!

July 24, 2017

Congratulations to Dr. Brandon Giles for passing his PhD defense exam!