Robert Meulenberg

Professor of Physics (Currently IPA at NSF)

Address: 5708 ESRB-Barrows, Room 251
Telephone: 207.581.2245
Email: robert.meulenberg@maine.edu

Research Overview

Education:

• 2002 Ph.D., University of California, Santa Barbara
• 1998  B.S., Florida State University

Research Interests:

• Electronic structure of nanoscale materials
• Surface and interfacial physics of nanostructures
• Novel materials for alternative energy applications
• Magnetometry and magnetic materials
• Synchrotron radiation (x-ray absorption, photoemission, and emission)

In the most general terms, the Meulenberg research group is involved in the understanding of both fundamental and applied physics and chemistry of nanoscale materials.  Meulenberg’s group currently has projects ranging from semiconductor plasmonics, nanomagnetism, silicon photonics, and mesoscopic chemistry and physics.  In addition, Meulenberg’s group has played an important role in utilizing element specific spectroscopic tools, such as x-ray spectroscopy, to probe the complex chemistry and physics of low dimensional solids.

To date, the Meulenberg research group has made large strides and impact in using advanced characterization methods towards probing the electronic structure of a host of nanoscale materials.  Most of the methods employed by the group involve synchrotron-based x-ray spectroscopy (absorption, emission, photoemission).  Most recently, Meulenberg and his students have been exploring both in situ/operando studies of chemical processes using x-ray absorption as well as utilizing time resolved (pump/probe) x-ray spectroscopy to probe charge carrier dynamics in nanomaterials.  To perform these measurements, travel to national or international facilities with synchrotron radiation sources is required.  Prof. Meulenberg has been successful in securing beamtime by writing user proposals that undergo a highly competitive and peer reviewed process.  Since his appointment began at UMaine, Meulenberg and his students have been awarded over 30 different synchrotron beamtimes in the United States, Canada, and Brazil.  In house, the group also has strong efforts in using magnetometry to probe magnetism and superconductivity in nanoscale materials.

Affiliated Research Links:

• Advanced Photon Source
• The Materials Research Collaborative Access Team (MRCAT)

Current and Past Research Sponsors:

 

Recent Publications:

“Mechanistic Insight into Copper Cation Exchange in Cadmium Selenide Semiconductor Nanocrystals using X-ray Absorption Spectroscopy.” A. Khammang, J. T. Wright, R. W. Meulenberg, submitted June 2020.

“Decoupling and Coupling of the Host-to-Dopant Interaction by Manipulating Dopant Movement in Core/Shell Quantum Dots.” E. Hofman, A. Khammang, J. T. Wright, Z-J Li, P. F. McLaughlin, A. H. Davis, A. Chakraborty, R. W. Meulenberg, W. Zheng, J. Phys. Chem. Lett., ASAP article (2020).

“Porous Organic Polymer Nanotrap for Efficient Extraction of Palladium.” B. Aguila, Q. Sun, H. C. Cassady, C. Shan, Z. Liang, A. M. Al-Enizic, A. Nafadyc, J. T. Wright, R. W. Meulenberg, S. Ma, Angew. Chem. Int. Ed., Early View article (2020).

“Exciton Energy Shifts and Tunable Dopant Emission in Manganese Doped Two-Dimensional CdS/ZnS Core/Shell Nanoplatelets.” A. H. Davis, E. Hofman, K. Chen, Z-J Li, A. Khammang, H. Zamani, J. M. Franck, M. M. Maye, R. W. Meulenberg, W. Zheng, Chem. Mater., 31, 2516-2523 (2019).

“Complete Dopant Substitution by Spinodal Decomposition in Mn-Doped Two-Dimensional CsPbCl₃Nanoplatelets.” Z-J Li, E. Hofman, A. H. Davis, A. Khammang, J. T. Wright, B. Dzikovski, R. W. Meulenberg, W. Zheng, Chem. Mater., 30, 6400-6409 (2018).

“Nature of the positron state in CdSe quantum dots.” W. Shi, V. Callewaert, B. Barbiellini, R. Saniz, W. Egger, M. Dickmann, C. Hugenschmidt, B. Shakeri, R. W. Meulenberg, E. Brück, B. Partoens, A. Bansil, S. W.H. Eijt, Phys. Rev. Lett., 057401 (2018).

“New insights into the nanostructure of innovative thin film solar cells gained by positron annihilation spectroscopy.” S. W. H. Eijt, W. Shi, A. Mannheim, M. Butterling, H. Schut, W. Egger, C. Hugenschmidt, B. Shakeri, R. W. Meulenberg, B. Barbiellini, A. Bansil, J. Melskens, M. Zeman, A.M.H.Smets, M.Kulback, D.Cahen, E.Brück, Journal of Physics: Conference Series, 791, 012021 (2017).

“Implications of Orbital Hybridization on the Electronic Properties of Doped Quantum Dots: the case of Cu:CdSe.”  J. T. Wright, K. Forsythe, J. Hutchins, R. W. Meulenberg, Nanoscale, 8, 9417-9424 (2016).

“Eu³⁺ Doped ZnM₂O₄ (M = Al³⁺, Ga³⁺) Nanospinels, an efficient Red Phosphor.” M. E. Foley, R. W. Meulenberg, J. McBride, G. F. Strouse, Chem. Mater. 27, 8362-8374 (2015).

“A closer look into the traditional purification process of CdSe semiconductor quantum dots.” B. Shakeri, R.W. Meulenberg, Langmuir, 31, 13433-13440 (2015).

“Nanostructure and Bonding of Zirconium Diboride Thin Films by x-ray Absorption Spectroscopy.” D. M. Stewart, R. W. Meulenberg, R. J. Lad, Thin Solid Films, 596, 155-159 (2015).

“In situ XANES and EXAFS Analysis of Redox Active Fe Center Ionic Liquids.” C. Apblett, D. M. Stewart, R. T. Fryer, J. C. Sell, H. D. Pratt III, T. M. Anderson, R. W. Meulenberg, Electrochim. Acta, 185, 156-161 (2015).

“Mechanism of Initiation in the Phillips’ Ethylene Polymerization Catalyst: Redox Processes Leading to the Active Site.”  C. Brown, J. Krzystek, R. Achey, R. Fu, R. W. Meulenberg, M. Polinski, N. Peek, Y. Wang, B. van de Burgt, S. Profeta, Jr., A. E. Stiegman, S. L. Scott, ACS Catal., 5, 5574–5583 (2015).

Updated: August 2020