Article: Fully Refereed

1.            * “Anomalous organic magnetoresistance from competing carrier-spin-dependent interactions with localized electronic and nuclear spins”, Y. Wang, N. J. Harmon, K. Sahin-Tiras, M. Wohlgenannt, and M. E. Flatté, Physical Review B Rapid Communications, accepted for publication.

 

2.            * “Organic Magnetoelectroluminescence for Room Temperature Transduction between Magnetic and Optical Information”, Nature Commun. 5, 3609 ( 2014 ).

 

3.            **” Including fringe fields from a nearby ferromagnet in a percolation theory of organic magnetoresistance”, N. J. Harmon, F. Macia, F. Wang, M. Wohlgenannt, A. D. Kent, and M. E. Flatté, Physical Review B 87, 121203(R) (2013)

 

4.            * “Hysteretic control of organic conductance due to remanent magnetic fringe fields”, F. Macia, F. Wang, N. J. Harmon, M. Wohlgenannt, A. D. Kent, and M. E. Flatté, Appl. Phys. Lett. 102, 042408 (2013).

 

5.            *”Tuning the performance of organic spintronic devices using x-ray generated traps”, J. Rybicki, R. Lin, F. Wang, F, M. Wohlgenannt, C. He, T. Sanders, Y. Suzuki, Physical Review Letters  109, 076603   (2012)

 

6.            *“Magnetic fringe field control of electronic transport in an organic film”, F. Wang, F. Macia, M. Wohlgenannt, A. D. Kent, M. E. Flatte, Physical Review X 2, 021013 (2012).

 

7.            * “Magnetic-field effect in organic photoconductive devices studied by time-of-flight”, F. Wang, J. Rybicki, K. A. Hutchinson, M. Wohlgenannt, Physical Review B 83, 241202(R) (2011).

 

8.            *“Distinguishing between tunneling and injection regimes of ferromagnet/organic semiconductor/ferromagnet junctions”, R. Lin, F. Wang, J. Rybicki, M. Wohlgenannt, K. A. Hutchinson, Physical Review B 81, 195214 (2010)

 

9.            *“Spin-orbit coupling in singly charged pi-conjugated polymers”, J. Rybicki, M. Wohlgenannt, Physical Review B 79, 153202 (2009)

 

10.         *“Theory for Spin Diffusion in Disordered Organic Semiconductors”, P. A. Bobbert, W. Wagemans, F. W. A. van Oost, B. Koopmans, M. Wohlgenannt, Physical Review Letters 102, 156604 (2009)

 

11.         *“Magnetic field-effects in bipolar, almost hole-only and almost electron-only tris-(8-hydroxyquinoline) aluminum devices”, T. D. Nguyen, Y. Sheng, J. Rybicki, M. Wohlgenannt, Physical Review B 77, 235209 (2008).

 

12.         **“A two-site bipolaron model for organic magnetoresistance”, W. Wagemans, F. L. Bloom, P.A. Bobbert, M. Wohlgenannt, B. Koopmans, Journal of Applied Physics 103, 07F303 (2008).

 

13.         *“Device spectroscopy of magnetic field effects in a polyfluorene organic light-emitting diode”, T. D. Nguyen, J. Rybicki, Y. Sheng, M. Wohlgenannt, Physical Review B 77, 035210 (2008).

 

14.         *“Bipolaron mechanism for organic magnetoresistance”, P.A. Bobbert, T.D. Nguyen, F.W.A. van Oost, B. Koopmans, M. Wohlgenannt, Physical Review Letters 99, 216801 (2007).

 

15.         *“On the role of hydrogen in organic magnetoresistance: A study of C-60 devices”, T. D. Nguyen, Y. Sheng, M. Wohlgenannt, T. D. Anthopoulos, Synthetic Metals 157, 930-934 (2007).

 

16.         **“Comment on "Frequency response and origin of the spin-1/2 photoluminescence-detected magnetic resonance in a pi-conjugated polymer”, C. G. Yang, E. Ehrenfreund, M. Wohlgenannt, Z. V. Vardeny, Physical Review B 75, 246201 (2007).

 

17.         *“An 8 × 8 Pixel Array Pen-Input OLED Screen Based on Organic Magnetoresistance”, G. Veeraraghavan, T. D. Nguyen,Y. Sheng, O. Mermer, M. Wohlgenannt, IEEE Trans. Electr. Dev. 54, 1571-1577 (2007).

 

18.         *“Magnetic field effects on current, electroluminescence and photocurrent in organic light emitting diodes”, G. Veeraraghavan, T. D. Nguyen,Y. Sheng, O. Mermer, M. Wohlgenannt, J. Phys.-Cond. Mat. 19, 036209 (13 pages) (2007).

 

19.         *“The effect of spin-orbit coupling on magnetoresistance in organic semiconductors”, Y. Sheng, T. D. Nguyen, G. Veeraraghavan, O. Mermer, M. Wohlgenannt, Physical Review B 75, 035202 (6 pages) (2007).

 

20.         *“Hyperfine interaction and magnetoresistance in organic semiconductors”, Y. Sheng, T. D. Nguyen, G. Veeraraghavan G, O. Mermer, M. Wohlgenannt, S. Qiu, U. Scherf, Physical Review B 74 (4), 045213 (9 pages) (2006)

 

21.         *“Large magnetoresistance in nonmagnetic pi-conjugated semiconductor thin film devices”, O. Mermer, G. Veeraraghavan, T. L. Francis, Y. Sheng, D. T. Nguyen, M. Wohlgenannt, A. Kohler, M. K. Al-Suti, M. S. Khan, Physical Review B 72, 205202 (12 pages) (2005).

 

22.         *“Large magnetoresistance at room temperature in small molecular organic sandwich devices”, O. Mermer, G. Veeraraghavan, T. L. Francis, and M. Wohlgenannt, Solid State Communications 134, 631-636 (2005).

 

23.         *“Single-step-multiphonon-emission model of spin-dependent exciton formation in organic semiconductors”, M. Wohlgenannt and O. Mermer, Physical Review B, 71, 165111 (8 pages) (2005)

 

24.         *“Spectroscopic study of spin-dependent exciton formation rates in pi-conjugated semiconductors: Comparison with electroluminescence techniques”, C. Yang, Z. V. Vardeny, A. Köhler, M. Wohlgenannt, M. K. Al-Suti, and M. S. Khan, Physical Review B 70, 241202 (R, 4 pages) (2004).

 

25.         *“Large magnetoresistance at room temperature in semiconducting polymer sandwich devices”, T. L. Francis, O. Mermer, G. Veeraraghavan, and M. Wohlgenannt, New Journal of Physics 6, 185 (8 pages) (2004).

 

26.         *“Confined and delocalized polarons in pi-conjugated oligomers and polymers: A study of the effective conjugation length”, M. Wohlgenannt, X. M. Jiang, Z. V. Vardeny, Physical Review B 69, 241204 (R, 4 pages) (2004).

 

27.         *“Excitons, polarons, and laser action in poly(p-phenylene vinylene) films, R. Österbacka, M. Wohlgenannt, M. Shkunov, D. Chinn, Z. V. Vardeny, Journal of Chemical Physics 118, 8905-8916 (2003).

 

28.         **“Linear and nonlinear photoexcitation dynamics in pi-conjugated polymers”, O. Epshtein, Y. Eichen, E. Ehrenfreund, M. Wohlgenannt, Z. V. Vardeny, Physical Review Letters 90, 046804 (4 pages) (2003).

 

29.         *“Spin-dependent delayed luminescence from non-geminate polarons in pi-conjugated polymer films”, M. Wohlgenannt, C. Yang, Z.V. Vardeny, Physical Review B 66, 241201(R, 4 pages) (2002)

 

30.         **“Excited-state relaxation in pi-conjugated polymers”, S. V. Frolov, Z. Bao, M. Wohlgenannt, and Z. V. Vardeny, Physical Review B 65, 205209 (12 pages) (2002).

 

31.         *“Conjugation-length dependence of spin-dependent exciton formation in pi-conjugated oligomers and polymers”, M. Wohlgenannt, X.M. Jiang, Z.V. Vardeny, and R.A.J. Janssen, Physical Review Letters 88, 197401 (4 pages) (2002).

 

32.         **“Excitation dynamics in single molecular crystals of alpha -hexathiophene from femtoseconds to milliseconds”, Frolov, S.V.; Kloc, Ch.; Batlogg, B.; Wohlgenannt, M.; Jiang, X.; Vardeny, Z.V., Physical Review B 63, 205203 (12 pages) (2001).

 

33.         *“Formation cross-sections of singlet and triplet excitons in pi -conjugated polymers”, Wohlgenannt, M.; Tandon, K.; Mazumdar, S.; Ramesesha, S.; Vardeny, Z.V., Nature 409, 494-497 (2001).

 

34.         *“Film morphology and photophysics of polyfluorene”, Cadby, A.J.; Lane, P.A.; Mellor, H.; Martin, S.J.; Grell, M.; Giebeler, C.; Bradley, D.D.C.; Wohlgenannt, M.; An, C.; Vardeny, Z.V., Physical Review B 62, 15604-15609 (2000).

 

35.         **“Ultrafast spectroscopy of even-parity states in pi -conjugated polymers”, Frolov, S.V.; Bao, Z.; Wohlgenannt, M.; Vardeny, Z.V., Physical Review Letters 85, 2196-2199 (2000).

 

36.         **“Optical studies of triplet excitations in poly(p-phenylene vinylene)”, Osterbacka, R.; Wohlgenannt, M.; Chinn, D.; Vardeny, Z.V., Physical Review B 60, R11253-11256 (1999)

 

37.         *“Photogeneration and recombination processes of neutral and charged excitations in films of a ladder-type poly(para-phenylene)”, Wohlgenannt, M.; Graupner, W.; Leising, G.; Vardeny, Z.V., Physical Review B 60, 5321-5330 (1999).

 

38.         *“Photogeneration action spectroscopy of neutral and charged excitations in films of a ladder-type poly(para-phenylene)”, Wohlgenannt, M.; Graupner, W.; Leising, G.; Vardeny, Z.V., Physical Review Letters 82, 3344-3347 (1999).

Invited Articles

39.         *” Magnetoresistance in pi-conjugated organic sandwich devices with varying hyperfine and spin-orbit coupling strengths, and varying dopant concentrations”, T. D. Nguyen, Y. Sheng, J. Rybicki, G. Veeraraghavan, M. Wohlgenannt, J. Mater. Chem. 17, 1995–2001 (2007).

 

40.         *“Spin and magnetic field effects in organic semiconductor devices”, M. Wohlgenannt, Z. V. Vardeny, J. Shi J, T. L. Francis, X. M. Jiang, O. Mermer, G. Veeraraghavan, D. Wu, Z. H. Xiong, IEE Proceedings – Circuits, Devices and Systems 152, 385-392 (2005)

 

41.         *“Photophysics properties of blue-emitting polymers”, M. Wohlgenannt and Z.V. Vardeny, Synthetic Metals 125, 55-63 (2001).

 

42.         *“Polarons in ladder-type polymer films; recombination channels and electron-phonon coupling”, Wohlgenannt, M.; An, C.P.; Vardeny, Z.V., Journal of Physical Chemistry B 104, 3846-3850 (2000).

 

43.         *“Photophysics of excitation energy transfer in highly fluorescent polymers”, Wohlgenannt, M., Graupner, W., Wenzl, F.P., Tasch, S., List, E.J.W., Leising, G., Graupner, M., Hermetter, A., Rohr, U., Schlichting, P., Geerts, Y., Scherf, U., Mullen, K., Chemical Physics 227, 99-109 (1998)

Conference Proceeding, refereed

44.         *”A new twist on organic spintronics; controlling transport in organic sandwich devices using fringe-fields from ferromagnetic films”, Proc. SPIE 8813, Spintronics VI, 88130O (2013).

 

45.         *“Organic magnetoresistance studied in the time and frequency domain”, F. Wang, R. Lin, J. Rybicki, M. Wohlgenannt, SPIE conference proceedings series, SPIEP/64390/833318 (2012).

 

46.         **”Spin in organics: a new route to spintronics”, B. Koopmans, W. Wagemans, F. L. Bloom, P. A. Bobbert, M. Kemerink, M. Wohlgenannt, Philosphical Transactions of the Royal Society 369, 3602 (2011).

 

47.         *"Frequency dependence of organic magnetoresistance", F. Wang, J. Rybicki, R. Lin, K. A. Hutchinson, J. Hou, M Wohlgenannt, Synthetic Metals 161, 622 (2010)

 

48.         *"Organic spin-valves based on fullerene C60", R. Lin, F. Wang, M Wohlgenannt, C. He, X. Zhai, Y. Suzuki, Synthetic Metals 161, 553 (2010)

 

49.         *“Spin relaxation and magnetoresistance in disordered organic semiconductors”, P.A. Bobbert, T. D. Nguyen, W. Wagemans, F.W.A. van Oost, B. Koopmans, M. Wohlgenannt, Synthetic Metals 160, 223-229 (2010).

 

50.         *“ Spin-orbit coupling and spin relaxation rate in singly charged pi-conjugated polymer chains”, J. Rybicki, T. D. Nguyen, Y. Sheng, M. Wohlgenannt, Synthetic Metals 160, 280-284 (2010).

 

51.         *“ Device-spectroscopy of magnetic field effects in several different polymer organic light-emitting diodes”, T. D. Nguyen, Y. Sheng , J. Rybicki, G. Veeraraghavan, M. Wohlgenannt, Synthetic Metals 160, 320-324 (2010).

 

52.         *“Magnetoconductivity and magnetoluminescence studies in bipolar and almost hole-only sandwich devices made from films of a pi-conjugated molecule”,T. D. Nguyen, Y. Sheng, J. Rybicki, M. Wohlgenannt, Science and Technology of Advanced Materials 9, 024206 (2008).

 

53.         *“Magnetic field effects on current, electroluminescence and photocurrent in Alq3 organic light emitting diodes”, G. Veeraraghavan1, T. D. Nguyen, Y. Sheng, O. Mermer, M. Wohlgenannt, Advances in Science and Technology 52, 53-61 (2006).

 

54.         *“Large magnetoresistance at room temperature in organic semiconductor devices”, O. Mermer, M. Wohlgenannt, T. L. Francis, G. Veeraraghavan, IEEE Transactions on Magnetics 41, 3682-3684 (2005).

 

55.         *“Morphology-dependent optical properties of substituted poly(p-phenylene-ethynylene) (PPE) films”, X. M. Jiang, C. C. Wu, M. Wohlgenannt, W. Y. Huang, T. K. Kwei, Y. Okamoto, Z. V. Vardeny, Physica B 338, 235-239 (2003)

 

56.         *“Spin-dependent exciton formation rates in pi-conjugated oligomers and polymers”, M. Wohlgenannt, X. M. Jiang, Z. V. Vardeny, Physica B 338, 318-322 (2003).

 

57.         *“Photoinduced charge transfer in poly(p-phenylene vinylene) derivatives and carbon nanotube/C-60 composites”, C. Yang, M. Wohlgenannt, Z. V. Vardeny, W. J. Blau, A. B. Dalton, R. Baughman, A. A. Zakhidov, Physica B 338, 366-369 (2003)

 

58.         *“Spin-dependent polaron pair recombination in pi-conjugated polymers: enhanced singlet exciton densities”, M. Wohlgenannt, X. M. Jiang, C. Yang, O. J. Korovyanko, Z. V. Vardeny, Synthetic Metals 139, 921-924 (2003).

 

59.         *“Spin-dependent exciton formation in pi-conjugated polymers and oligomers”, Wohlgenannt, M.; Jiang, X.M.; Vardeny, Z.V, Synthetic Metals 137, 1069-1071 (2003).

 

60.         **“Dispersive nonlinear dynamics of photoexcitations in pi-conjugated polymers”, Ehrenfreund E, Epshtein O, Eichen Y, Wohlgenannt M, Vardeny ZV, Synthetic Metals 137, 1363-1365 (2003).

 

61.         *“Hexathiophene single crystals: luminescence and magnetic resonance”, Wohlgenannt, M.; Jiang, X.M.; Vardeny, Z.V.; Frolov, S.V.; Kloc, C.; Batlogg, Synthetic Metals (International Conference on Science and Technology of Synthetic Metals) 119, 647-648 (2001).

 

62.         *“Long-lived photoexcitations in alpha -hexathiophene single crystals”, Wohlgenannt, M.; Vardeny, Z.V.; Frolov, S.V.; Kloc, C.; Batlogg, B., Synthetic Metals (Fourth International Topical Conference on Optical Probes of pi-Conjugated Polymers and Photonic Crystals) 116, 181-184 (2001).

 

63.         **“Multiple pulse transient spectroscopy in luminescent pi -conjugated polymers”, Frolov, S.V.; Bao, Z.; Wohlgenannt, M.; Vardeny, Z.V., Synthetic Metals (Fourth International Topical Conference on Optical Probes of pi-Conjugated Polymers and Photonic Crystals) 116, 5-7 (2001).

 

64.         **“Studies of optical transitions related to pi -conjugated polymers and laser dyes infiltrated in opal photonic crystals”, Eradat, N.; Wohlgenannt, M.; Vardeny, Z.V.; Zakhidov, A.A.; Baughman, R.H., Synthetic Metals (Fourth International Topical Conference on Optical Probes of pi-Conjugated Polymers and Photonic Crystals) 116, 509-513 (2001).

 

65.         *“Spectroscopy of conducting and insulating ladder-type poly(para-phenylene) device structures”, Wohlgenannt, M.; List, E.J.W.; Zenz, C.; Leising, G.; Graupner, W.; Vardeny, Z.V., Synthetic Metals (Fourth International Topical Conference on Optical Probes of pi- Conjugated Polymers and Photonic Crystals), 116, 353-356 (2001).

 

66.         **“Density of states of ensembles of conjugated molecules deduced from the photobleaching and absorption spectra”, Graupner, W., Wohlgenannt, M., Synthetic Metals (Fourth International Topical Conference on Optical Probes of pi-Conjugated Polymers and Photonic Crystals), 116, 193-197 (2001).

 

67.         *“Optical studies of photoexcitations of poly(9,9-dioctyl fluorene)”, Cadby, A.J.; Lane, P.A.; Wohlgenannt, M.; An, C.; Vardeny, Z.V.; Bradley, D.D.C., Synthetic Metals (2nd International Conference on Electroluminescence of Molecular Materials and Related Phenomena), 111-112, 515-518 (2000).

 

68.         *“Singlet fission in luminescent and nonluminescent pi -conjugated polymers”, Wohlgenannt, M.; Graupner, W.; Osterbacka, R.; Leising, G.; Comoretto, D.; Vardeny, Z.V., Synthetic Metals (International Conference on Science and Technology of Synthetic Metals) 101, 267-268 (1999).

 

69.         **“Optical spectroscopies of excited states in poly(para phenylene vinylene)”, Osterbacka, R.; Shkunov, M.; Chinn, D.; Wohlgenannt, M.; DeLong, M.; Viner, J.; Vardeny, Z.V., Synthetic Metals (International Conference on Science and Technology of Synthetic Metals) 101, 226-229 (1999).

 

70.         **“Optimizing hexaphenyl thin film quality for opto-electronic applications by heat treatment”, Resel, R.; Graupner, W.; Hochfilzer, C.; Koch, N.; Meghdadi, F.; Tasch, S.; Wohlgenannt, M.; Leising, G.; Reichmann, K., Proceedings of the XVII International Conference on Applied Crystallography, 413 (1998)

 

71.         **“Dynamics of photoexcitations in highly fluorescent organic guest-host-systems”, List, E.J.W.; Graupner, W.; Wohlgenannt, M.; Leising, G.; Partee, J.; Shinar, J.; Schlichting, P.; Rohr, U.; Geerts, Y.; Scherf, U.; Mullen, K., Optical Materials (Materials, Physics and Devices for Molecular Electronics and Photonics. Symposium of the E-MRS Spring Conference) 9, 494-497 (1998).

Published Reviews of Scholarship

72.         *” Intrinsic magnetic field effects in organic semiconductors: overview and recent developments”, M. Wohlgenannt, P.A. Bobbert, B. Koopmans, MRS Bulletin 39, 590 – 595 (2014).

 

73.         *“Organic magnetoresistance and spin diffusion in organic semiconductor thin film devices”, M. Wohlgenannt, Physica status solidi – RRL 6, 229-242 (2012)

 

74.         *“Polarons in pi-conjugated semiconductors: absorption spectroscopy and spin-dependent recombination”, M. Wohlgenannt, Physica Status Solidi A 201, 1188-1204 (2004).

 

75.         *“Spin-dependent exciton formation rates in pi-conjugated materials”, M. Wohlgenannt and Z. V. Vardeny, Journal of Physics: Condensed Matter 15, R83-R107 (2003)

 

Invited Book Chapter

76.         *"Magnetoresistance and spin transport in organic semiconductor devices", M. Wohlgenannt, P. A. Bobbert, B. Koopmans, in "Organic Spintronics”, Z. V. Vardeny ed., Taylor and Francis (2010).

 

77.         *"Spectroscopy of Photoexcitations in Conjugated Polymers", Z. V. Vardeny and M. Wohlgenannt, in "Semiconducting Polymers" Wiley-VCH (2010).

 

78.         *“Magnetoresistance and spin-effects in organic light-emitting diodes”, M. Wohlgenannt, Z. V. Vardeny, in "Handbook of Organic Electronics and Photonics", ed. H. S. Nalwa, American Scientific Publishers (www.aspbs.com), 2007.

 

79.         *“Spectroscopy of long lived photoexcitations in pi-conjugated semiconductors”, M. Wohlgenannt, E. Ehrenfreund, Z. V. Vardeny, in “Photophysics of molecular materials”, ed. G. Lanzani, Wiley-VCH, 2005.

 

80.         *“Polarons in pi-conjugated semiconductors: absorption spectroscopy and spin-dependent recombination”, M. Wohlgenannt, in “Physics of organic semiconductors”, ed. W. Brutting, Wiley-VCH, 2005.

International and National Presentations

Invited Plenary talks

 

1.            International Workshop on Organic Magneto-Optics, Magneto-Electronics, and Magneto-Thermoelectrics, Wuhan, China, October 2013, “Controlling transport and electroluminescence in organic sandwich devices and molecular wires”

 

2.            Spin in Organic Semiconductors meeting III (SPINOS III), Amsterdam, The Netherlands, September 2010, “Organic magnetoresistance”

 

3.            CECAM workshop: Modelling electronic processes in molecular scale devices September 2003 Lyon, France, Invited plenary talk: “Polarons in organic semiconductor films and their spin-dependent recombination”, M. Wohlgenannt and Z. V. Vardeny.

 

Invited talks

 

4.            Organic semiconductor spintronics: Utilising triplet excitons in organic electronics, organized by The Royal Society, London, September 2014, “Singlet-to-triplet conversion utilizing hyperfine as well as ferromagnetic fringe fields”.

 

5.            Meeting for celebrating the 10th anniversary of the organic spin-valve Nature paper, August 2014, Salt Lake City, UT, “Organic magnetoelectroluminescence for room temperature transduction between magnetic and optical information”

 

6.            Energy Materials Nanotechnology (EMN) Fall Meeting 2013, December 2013, Orlando, FL, “Controlling transport and electroluminescence in organic sandwich devices and molecular wires”

 

7.            6th Scientific Workshop “Towards Molecular Spintronics”, October 2013, Chemnitz, Germany, “Controlling transport and electroluminescence in organic sandwich devices using spin effects”

 

8.            12th European Conference on Molecular Electronics, September 2013, London, UK, “Controlling transport and electroluminescence in organic sandwich devices using spin effects”

 

9.            SPIE Optics and Photonics, August 2013, San Diego, CA, “A new twist on organic spintronics: Controlling transport and electroluminescence in organic sandwich devices using fringe fields from ferromagnetic films”

 

10.         Spin-Chemistry Meeting (SCM2013) April 2013, Bad Hofgastein, Austria, “Organic Magneto-Resistance in the Presence of Strong Magnetic-field Gradients”

 

11.         2nd Annual World Congress of Nano-S&T (Nano S&T-2012), October 2012, Qingdao, China, “Studies of magnetic field sensors based on organic spintronic effects”

 

12.         Spin in Organic Semiconductors meeting IV (SPINOS IV), London, UK, September 2012, “Fringe-field effects in organic spintronics”

 

13.         American Physical Society March Meeting, Boston, Feb. 2012, “A new twist on organic spintronics: Controlling transport in organic sandwich devices using fringe fields from ferromagnetic films”

 

14.         Photonics and Optoelectronics Meeting (POEM), Wuhan, China, Nov. 2011, “Spin-dynamics and magnetic field effects in organic semiconductor diodes”

 

15.         Spin Chemistry Meeting, Noordwijk, The Netherlands, May 2011, “Magnetic-field effect in organic photoconductive devices studied by time-of-flight”

 

16.         Spin Chemistry Meeting, St. Catherines, ON, Canada, June 2009, “Magnetic-field effects in organic semiconductors”

 

17.         Excited States Processes In Electronic And Bio-Materials, Santa Fe, NM, June 2009, “Spin-orbit coupling and magnetoresistance in organic semiconductor spintronic devices”

 

18.         Optical Probes in Conjugated Polymers Meeting, Beijing, China, June 2009, “Spectroscopy of magnetic field effects”

 

19.         36th International Conference On Metallurgical Coatings And Thin Films, April 2009, San Diego, CA, Invited Talk “Large Magnetoresistance in Organic Semiconductor Thin Film Devices”, M. Wohlgenannt

 

20.         Midwest Solid State Physics Meeting, Iowa City, IA, April 2009, “Magnetoresistance and spin-transport in organic semiconductor thin film devices”

 

21.         American Physical Society Meeting, Pittsburgh, PA, Invited Talk: “Magnetoresistance and Spin Transport in Organic Semiconductor Devices”, M. Wohlgenannt

 

22.         International Conference on Synthetic Metals (ICSM), July 2008, Recife, Brazil, Invited Talk: “Device Spectroscopy of Magnetic-Field-Effects in Organic Light-Emitting Diodes”, M. Wohlgenannt

 

23.         Meeting of the Society of Electron Spin Science and Technology (SEST 2007), November 2007, Shizuoka, Japan, Invited Talk: “Characterization and Application of Large Magnetoresistance in Organic Semiconductors”, M. Wohlgenannt

 

24.         International Conference on Magneto-Science (ICMS2007), November 2007, Hiroshima, Japan, Invited Talk: “Characterization and Application of Large Magnetoresistance in Organic Semiconductors”, M. Wohlgenannt

 

25.         Device Research Conference, June 2007, South Bend, IN, Invited Talk, “Characterization and Application of Large Magnetoresistance in Organic Semiconductors”, M. Wohlgenannt

 

26.         Optical Probes of Conjugated Polymers, June 2007, Turku, Finland, Invited Talk: “Device-spectroscopy of magnetic field effects in organic light-emitting diodes”, M. Wohlgenannt

 

27.         American Physical Society Meeting, March 2007, Denver, CO Invited Talk: “Characterization and Application of Large Magnetoresistance in Organic Semiconductors”, M. Wohlgenannt

 

28.         CIMTEC 2006: June 2006 Acireale, Italy Invited Talk: “Very large magnetoresistance in non-magnetic organic light-emitting diodes”, M. Wohlgenannt.

 

29.         Frontiers in Optics 2005: October 2005 Tucson, AZ Invited talk: “Very large magnetoresistance in non-magnetic organic light-emitting diodes”, M. Wohlgenannt.

 

30.         Nanoforum DC 2005: April 2005 Alexandria, VA Invited talk: “Very large magnetoresistance in non-magnetic organic light-emitting diodes”, M. Wohlgenannt.

 

31.         Workshop on Fundamental Research Needs in Organic Electronic Materials (sponsored by DOE): May 2003 Salt Lake City, UT Invited talk: “Spin-dependent exciton formation and OLED quantum efficiency”, M. Wohlgenannt and Z. V. Vardeny.

 

32.         International Conference on Science and Technology of Synthetic Metals: June/July 2002 Shanghai, China Invited talk: “Spin-dependent exciton formation in pi-conjugated polymers and oligomers”, M. Wohlgenannt and Z. V. Vardeny.

 

33.         American Physical Society March meeting: March 2002 Indianapolis, IN Invited talk: “Studies of spin-dependent exciton formation from charge recombination in pi-conjugated polymers”, M. Wohlgenannt and Z. V. Vardeny.

 

34.         American Physical Society March meeting: March 2000 Minneapolis, MI Invited talk: “Photophysics of blue-emitting polymer films and LEDs”, M. Wohlgenannt and Z. V. Vardeny.

 

Colloquia/Seminars

 

35.         Technical University of Eindhoven, NL, Solid State Seminar, March 2013, “Fringe-field effects in organic spintronics”

 

36.         Truman State University, Physics Colloquium, February 2013, “Magnetic field effects in organic semiconductors: from pen-input displays to bird navigation”, M. Wohlgenannt

 

37.         University of Southern Florida, Colloquium, December 2011, “Organic spintronics: spin-dependent processes and magnetoresistance in organic semiconductors”, M. Wohlgenannt

 

38.         University of Leiden, Spin Chemistry Seminar, September 2010: “Organic magnetoresistance”, M. Wohlgenannt

 

39.         Technische Universiteit Eindhoven, Solid State Seminar, Oct 2008: “Hyperfine Coupling, Spin-Orbit Coupling and Magnetoresistance in Organic Semiconductor Devices”, M. Wohlgenannt.

 

40.         University of Arizona, colloquium, Oct 2007: “Organic Magnetoresistance”, M. Wohlgenannt.

 

41.         University of Arizona, low energy physics seminar, Oct 2007: “Theory of Organic Magnetoresistance”, M. Wohlgenannt.

 

42.         University of Iowa, physical chemistry seminar, Nov 2006: “Theory of Organic Magnetoresistance”, M. Wohlgenannt.

 

43.         University of Iowa, OSTC seminar series, June 2006: “Very large magnetoresistance in non-magnetic organic light-emitting diodes”, M. Wohlgenannt.

 

44.         University of Linz, Austria, physical chemistry seminar, June 2006: “Very large magnetoresistance in non-magnetic organic light-emitting diodes”, M. Wohlgenannt.

 

45.         University of Wisconsin, colloquium: November 2005, Madison, WI: “Very large magnetoresistance in non-magnetic organic light-emitting diodes”, M. Wohlgenannt

 

46.         University of Illinois, colloquium: November 2005, Chicago, IL: “Very large magnetoresistance in non-magnetic organic light-emitting diodes”, M. Wohlgenannt

 

47.         University of Iowa, solid state seminar series: November 2004, Iowa City, IA: “A novel large magnetoresistance effect in polymer sandwich devices”, O. Mermer, M. Wohlgenannt, T. L. Francis

 

48.         University of Iowa, solid state seminar series: September 2004, Iowa City, IA: “Single-step-multiphonon-emission model of spin-dependent exciton formation in organic semiconductors”, M. Wohlgenannt, O. Mermer

 

49.         University of Iowa, solid state seminar series: January 2004, Iowa City, IA: “Weak localization in polymer sandwich devices?”, M. Wohlgenannt, O. Mermer, G. Veeraraghavan, T. L. Francis

 

50.         University of Iowa, solid state seminar series: September 2003, Iowa City, IA: “Confined and delocalized polarons in pi-conjugated oligomers and polymers: A study of the effective conjugation length”, M. Wohlgenannt, Z. V. Vardeny

 

51.         University of Linz, physical chemistry seminar: July 2003, Linz, Austria: “Spin-dependent Exciton Formation in Organic Semiconductors”, M. Wohlgenannt, Z. V. Vardeny

 

52.         Technical University of Graz, solid state physics seminar: July 2003, Graz, Austria: “Spin-dependent Exciton Formation in Organic Semiconductors”, M. Wohlgenannt, Z. V. Vardeny

 

53.         University of Iowa, physical chemistry seminar: April 2003, Iowa City, IA: “Spin-dependent Exciton Formation in Organic Semiconductors”, M. Wohlgenannt, Z. V. Vardeny

 

54.         University of Northern Iowa, Physics Colloqium: March 2003, Waterloo, IA: “Spin-dependent Exciton Formation in Organic Semiconductors”, M. Wohlgenannt, Z. V. Vardeny

 

55.         University of Iowa, solid state seminar series: September 2002, Iowa City, IA: “The field of pi-conjugated polymers: A survey”, M. Wohlgenannt

​

 

56.         University of Missouri, Physics Colloqium: March 2002, Columbia, Missouri: “Spin-dependent Exciton Formation in Organic Semiconductors”, M. Wohlgenannt, Z. V. Vardeny

 

57.         University of Iowa, solid state seminar: March 2002, Iowa City, IA: “Spin-dependent Exciton Formation vs. Triplet Exciton Harvesting”, M. Wohlgenannt, Z. V. Vardeny

 

58.         Tulane University, Physics Colloqium: February 2002, New Orleans, Louisiana: “Spin-dependent Exciton Formation in Organic Semiconductors”, M. Wohlgenannt, Z. V. Vardeny

 

59.         University of Nebraska, Physics Colloqium: February 2002, Lincoln, NE: “Spin-dependent Exciton Formation in Organic Semiconductors”, M. Wohlgenannt, Z. V. Vardeny

 

60.         Washington University in St. Louis, Physics Colloqium: January 2002, St. Louis, Missouri: “Spin-dependent Exciton Formation in Organic Semiconductors”, M. Wohlgenannt, Z. V. Vardeny

 

61.         Washington State University, Physics Colloqium: January 2002, Pullman, WA: “Spin-dependent Exciton Formation in Organic Semiconductors”, M. Wohlgenannt, Z. V. Vardeny

 

62.         University of Osaka, Electrical Engineering Seminar: January 2001, Osaka, Japan: “Formation cross-sections of singlet and triplet excitons in pi -conjugated polymers”, M. Wohlgenannt, Z. V. Vardeny

 

63.         University of Utah, Solid State Seminar: December 2000, Salt Lake City, UT: “Formation cross-sections of singlet and triplet excitons in pi -conjugated polymers”, M. Wohlgenannt, Z. V. Vardeny

 

Talks and posters

 

64.         Spin in Organic Semiconductors meeting IV (SPINOS IV), London, UK, September 2012, Talk: “Tuning the performance of organic spintronic devices using x-ray generated traps”, M. Wohlgenannt and R. Lin

 

65.         American Physical Society March Meeting, Dallas, TX, March 2011, Talk: “Magnetic fringe-field control of electronic transport in an organic film”, M. Wohlgenannt

 

66.         International Conference on Synthetic Metals 2006, Dublin, Ireland, July 2006, Talk: “Very large magnetoresistance in non-magnetic organic light-emitting diodes”, M. Wohlgenannt

 

67.         European MRS 2006, Strasbourg, France, April 2006, Talk: “Very large magnetoresistance in non-magnetic organic light-emitting diodes”, M. Wohlgenannt

 

68.         IMAG, Nagoya, Japan, April 2005, Talk: “Very large magnetoresistance in non-magnetic organic light-emitting diodes”, M. Wohlgenannt

 

69.         American Physical Society March meeting: March 2004 Montreal, Canada Talk: “Confined and delocalized polarons in pi-conjugated oligomers and polymers: A study of the effective conjugation length”, M. Wohlgenannt and Z. V. Vardeny.

 

70.         American Physical Society March meeting: March 2003 Austin, TX Talk: “Spin-dependent exciton formation in pi-conjugated polymers and oligomers”, M. Wohlgenannt and Z. V. Vardeny.

 

71.         Fifth International Topical Conference On Optical Probes Of Conjugated Polymers And Organic & Inorganic Nanostructures, Feb 2003 Venice, Italy Talk: “Spin-dependent exciton formation in pi-conjugated polymers and oligomers”, M. Wohlgenannt and Z. V. Vardeny.

 

72.         Sixth International Conference on Electrical Transport and Optical Properties of Inhomogeneous Media July 2002 Snowbird, Utah Talk: “Spin-dependent exciton formation in pi-conjugated polymers and oligomers”, M. Wohlgenannt and Z. V. Vardeny.

 

73.         2nd International Conference on Electroluminescence of Molecular Materials and Related Phenomena: September 2001 Los Angeles, CA Talk: “Enhanced singlet exciton yield from charge recombination in pi-conjugated polymers”, M. Wohlgenannt and Z. V. Vardeny.

 

74.         Excited State Processes in Electronic and Bio-Materials: August 2001 Los Alamos, NM Talk: “Enhanced singlet exciton yield from charge recombination in piconjugated polymers”, M. Wohlgenannt and Z. V. Vardeny.

 

75.         American Physical Society March meeting: March 2001 Seattle, WA Two talks: “Direct determination of singlet and triplet formation cross sections in pi-conjugated polymers”, M. Wohlgenannt and Z. V. Vardeny and “Optically detected magnetic resonance of organic single crystals”, M. Wohlgenannt and Z. V. Vardeny.

 

76.         International Conference on Science and Technology of Synthetic Metals: July 2000 Gastein, Austria Poster on “Optically detected magnetic resonance of organic single crystals”, M. Wohlgenannt and Z. V. Vardeny.

 

77.         Fourth International Topical Conference on Optical Probes of pi-Conjugated Polymers and Photonic Crystals: February 2000 Salt Lake City, UT Talk: ”Charge induced absorption spectroscopy of blue-emitting polymer LEDs” M. Wohlgenannt and Z. V. Vardeny, and poster on “Long-lived photoexcitations in sexi-thiophene single crystals”, M. Wohlgenannt and Z. V. Vardeny.

 

78.         American Physical Society March meeting: March 1999 Atlanta, GA Two talks: “Photogeneration of triplet excitons and polarons in mLPPP”, M. Wohlgenannt and Z. V. Vardeny and “Photophysics and morphology of Poly-Fluorene films”, M. Wohlgenannt and Z. V. Vardeny.

 

79.         International Conference on Science and Technology of Synthetic Metals: July 1998 Montpellier, France Poster on “Photogeneration of triplet excitons and polarons”, M. Wohlgenannt and Z. V. Vardeny.

 

80.         American Physical Society March meeting: March 1998 Los Angeles, CA Talk “Photophysics of a polymeric guest-host system”, M. Wohlgenannt and Z. V. Vardeny.

Patents

1.            Invention Disclosure D2014-0053 to UIRF by Markus Wohlgenannt and M. E. Flatté (University of Iowa) and A. D. Kent (New York University). Preliminary patent application is presently being written by Smith, Gambrell & Russell law firm.

2.            “Magneto Resistive Elements and Methods for Manufacture and Use of Same”, inventors: Markus Wohlgenannt, Thomas Francis, Ömer Mermer, and Govindarajan Veeraraghavan. US patent issued in 2011.