Field of Research: Nanoscience
Ph.D. : University of Amsterdam
Terahertz spectroscopy of biomolecules in liquid water
Biomolecules solvated in their natural, liquid water environment exhibit a strong absorption in the terahertz region that contains information on their global and subglobal collective vibrational modes and global dynamical correlations among solvent water molecules and the biomolecule. Measurements in this region, however, are challenging due to the strong water absorption and often severe interference artifacts. In response, we have developed a highly sensitive, frequency domain, high resolution, vector network analyzer-based spectrometer that supports the accurate measurements of both the absorbance and refractive index of aqueous biomolecular solutions over this important spectral region. Using this system we have explored the complex dielectric response of solvated lysozyme protein over range 0.5 GHz to 1.1 THz as a means of probing the protein’s hydration shell and the large-scale dynamics. We make a direct comparison to the existing theoretical calculations and investigate the dependence of the low frequency dynamics on protein concentration and solvent pH. The discoveries shed light on the macromolecular motions in a biologically relevant water environment.
Domain motion due to the lowest frequency modes in
lyzsozyme and the hydration shell around the protein
Nanostructures for Terahertz frequencies
Following the success of III-V quantum cascade lasers (QCLs) at both mid-infrared and far-infrared (terahertz) frequencies, there is considerable interest in the development of silicon-based quantum cascade devices for low-cost sources and optoelectronic integration with other circuitry. The indirect band gap that has hindered interband emitter development in Si, Si1−xGex, and Ge does not affect QCLs, as they rely on carrier transitions within the same (conduction or valence) band rather than on exciton recombination across the band gap. Indeed, SiGe-based materials have a major advantage over III-V’s for this type of device, in that phonons are nonpolar, and this reduces the principal nonradiative scattering rate that limits the efficiency in III-V devices. This is particularly true at photon energies below the optical phonon energy which range is the subject of the present work. If a QCL could be realized in Si/SiGe, the lack of polar optical phonon scattering, the lower free carrier absorption, and the higher thermal conductivity of Si could allow significantly higher operating temperatures in the terahertz range. Moreover, there could be lower manufacturing costs involved with the mature silicon process technology.
Quantum Information Processing
One of the great successes of quantum physics which is the long-lived Rydberg states of donor and acceptor impurities in silicon. Of particular interest because they can be exploited for quantum control of one atom by another are excited Rydberg states, where wavefunctions are expanded from their ground state extents of below 0.1 nm to several nm and even beyond; this allows atoms far enough apart to be noninteracting in their ground states to strongly interact in their excited states. For eventual application, a solid state implementation is very desirable, and we demonstrated the coherent control of impurity wavefunctions in the most ubiquitous donors and acceptors in a semiconductor, namely the phosphorous- and boron-doped silicon. Our experiments take advantage of a free-electron laser to stimulate and observe population times, photon echoes, the orbital analog of the Hahn spin echo, Rabi oscillations.
2. N. Q. Vinh, P. T. Greenland, K. Litvinenko, B. Redlich, A. F. G. van der Meer, S. A. Lynch, M. Warner, A. M. Stoneham, G. Aeppli, D. J. Paul, C. R. Pidgeon and B. N. Murdin, P. Natl. Acad. Sci. USA 105, 10649 (2008); e-print arXiv:0812.0148 (2008).
Photonic materials: Rare-earth doped semiconductors (GaN:Er and Si:Er)
Rare earth (RE) doped semiconductors have played an important role in various optoelectronic and photonic applications, ranging from emitting elements in solid-state lasers and in phosphors for color lamps and displays to optical fiber telecommunications and to quantum information processing. Among the various rare earth elements, Er has attracted a particular attention because the 4I13/2 to 4I15/2 transition involving nonbonding 4f shell electrons of the Er3+ ion occurs at the technologically important wavelength of 1.54 micrometer, matching the absorption minimum of silica-based optical fibers. GaN is expected to be an ideal host material for RE doping because it is a wide and direct bandgap semiconductor, which exhibits less thermal quenching and stronger RE emission at room temperature than RE-doped Si. As a result of a continuing research effort, GaN:Er-based light emitting diodes have now been developed.
Structure and dynamics of aqueous solvation shells
Water plays an important role in chemical and biological processes. In aqueous solutions, water molecules dissolve ionic compounds, charged chemical species by forming hydration shells around them. Here we have employed a vector network analyzer-based spectrometer to measure the complex dielectric response of liquid water and aqueous solutions with unprecedented precision over the range 0.5 GHz to 1.1 THz. In doing so, we have obtained statistically significant evidence that the dynamics of water over this frequency regime are best described in terms of three Debye relaxation processes with the characteristic times of 8.56, 1.10 ps and 179 fs (at 25.0oC). The relaxation time and the amplitude of these processes allow us to understand the structure and the dynamics of water in the hydration shells around ions.
(left) Due to the high polarity, water molecules close to the dissolved ions
from the hydration shells. (right) The relaxation time constants and amplitudes
vary with salt concentration provide insights into the mechanisms underlying
these dynamic processes. The time constants of all three Debye processes are
effectively independent of salt concentration. Their amplitudes, in contrast,
vary significantly with changing salt concentration: while the amplitude of the
slowest relaxation falls with rising salt concentrations, the amplitudes of the
faster components increase with increasing salt concentration.
Organic Solar Cells
Solar-cell technology based on conjugated polymer-fullerene composites continues to be of interest as a potential source of renewable energy. In particular, because of the light weight, mechanical flexibility, and potential for low-cost production of electronic devices fabricated from semiconducting polymers, high-efficiency polymer solar cells could have a major impact on energy needs. Although encouraging progress has been made in recent years with 3-5% power conversion efficiencies, this efficiency is not yet sufficient for large-scale implementation. Moreover, concerns about instability at elevated temperatures have hindered the path toward commercialization. The need to improve the device efficiency and thermal stability requires state-of-the-art fabrication and treatment under more rigorously defined conditions. Therefore experimental investigation of their photophysical properties, in particular of the photogeneration of charge carriers, will yield important information that can clarify the mechanism of formation and the fate of the primary excitations as well as provide a basis for photovoltaic applications
71. V. X. Ho, T. M. Al Tahtamouni, H. X. Jiang, J. Y. Lin, J. M. Zavada, and N. Q. Vinh
Room-temperature lasing action in GaN quantum wells in the infrared 1.5 μm region
ACS Photonics 5, xxx (2018).
70. J. R. Mahan, N. Q. Vinh, V. X. Ho, and N. B. Munir
Monte Carlo ray-trace diffraction based on the Huygens-Fresnel principle
Applied Optics 57, D56 (2018).
69. (Conference paper) J. R. Mahan, N. Q. Vinh, and K. J. Priestley
An Application of the Monte Carlo Ray-Trace Method with Bidirectional Reflection
The 3rd Thermal and Fluids Engineering Conference, 2018, Fort Lauderdale, FL (2018).
65. V. X. Ho, T. V. Dao, H. X. Jiang, J. Y. Lin, J. M. Zavada, S. A. McGill, and N. Q. Vinh
Photoluminescence quantum efficiency of Er optical centers in GaN epilayers
Scientific Reports, 7 39997 (2017).
64. V. X. Ho, S. P. Dail, T. V. Dao, H. X. Jiang, J. Y. Lin, J. M. Zavada, and N. Q. Vinh
Temperature dependence studies of Er optical centers in GaN epilayers grown by MOCVD
MRS Advances (2017).
63. N. Q. Vinh
Probe conformational dynamics of proteins in aqueous solutions by terahertz spectroscopy
Proc. of SPIE 9934, 99340R (2016), (Invited paper).
62. D. K. George, A. Charkhesht, O. A. Hull, A. Mishra, D. G.S. Capelluto, K. R. Mitchell-Koch, and N. Q. Vinh
New Insights into the Dynamics of Zwitterionic Micelles and Their Hydration Waters by Gigahertz-to-Terahertz Dielectric Spectroscopy
The Journal of Physical Chemistry B 120, 10757 (2016).
61. D. K. George, M. D. Hawkins, H. X. Jiang, J. Y. Lin, J. M. Zavada, and N. Q. Vinh
Optical excitation of Er centers in GaN epilayers grown by MOCVD
Proc. of SPIE 9744, 97440V (2016), (Invited paper).
60. D. K. George, A. Charkhesht, and N. Q. Vinh
New terahertz dielectric spectroscopy for the study aqueous solutions
Review of Scientific Instruments 86, 123105 (2015), e-print arXiv:1507.05322 (2015).
59. D. K. George, M. D. Hawkins, M. McLaren, H. X. Jiang, J. Y. Lin, J. M. Zavada, and N. Q. Vinh
Excitation mechanisms of Er optical centers in GaN epilayers
Appl. Phys. Lett. 107, 171105 (2015), e-print arXiv:1507.05119 (2015).
58. N. Q. Vinh, M. S. Sherwin, S. J. Allen, D. K. George, A. J. Rahmani, and K. W. Plaxco
High-precision gigahertz-to-terahertz spectroscopy of aqueous salt solutions as a probe of the femtosecond-to-picosecond dynamics of liquid water
and Supporting Information for the J. Chem. Phys. 142,164502
J. Chem. Phys. 142, 164502 (2015), e-print arXiv:1505.07100 (2014).
57. N. Q. Vinh, B. Redlich, A. F. G. van der Meer, C. R. Pidgeon, P. T. Greenland, S. A. Lynch, G. Aeppli, and B. N. Murdin
Time-resolved dynamics of shallow acceptors transitions in silicon
Phys. Rev. X 3, 011019 (2013).
56. G. C. Dyer, G. R. Aizin, S. Preu, N. Q. Vinh, S. J. Allen, J. L. Reno, and E. A. Shaner
Inducing an incipient terahertz finite plasmonic crystal in coupled two dimensional plasmonic cavities
Phys. Rev. Lett. 109, 126803 (2012).
55. S. A. Lynch, P. T. Greenland, A. F. G. van der Meer, B. N. Murdin, C. R. Pidgeon, B. Redlich, N. Q. Vinh, and G. Aeppli
Quantum control in silicon using coherent THz pulses
Proc. of SPIE 8496, 84960O (2012), (Invited paper).
54. S. Preu, S. Kim, R. Verma, P. G. Burke, N. Q. Vinh, M. S. Sherwin, and A. C. Gossard
Terahertz Detection by a Homodyne Field Effect Transistor Multiplicative Mixer
IEEE Transactions on Terahertz Science and Technology 2, 278 (2012).
53. G. C. Dyer, S. Preu, G. R. Aizin, J. Mikalopas, A. D. Grine, J. L. Reno, J. M. Hensley, N. Q. Vinh, A. C. Gossard, M. S. Sherwin, S. J. Allen, and E. A. Shaner
Enhanced performance of resonant sub-terahertz detection in a plasmonic cavity
Appl. Phys. Lett. 100, 083506 (2012).
52. N. Q. Vinh, S. J. Allen, and K. W. Plaxco
Dielectric spectroscopy of proteins as a quantitative experimental test of computational models of their low-frequency harmonic motions
J. Am. Chem. Soc. 133, 8942 (2011).
51. G. C. Dyer, N. Q. Vinh, S. J. Allen, G. R. Aizin, J. Mikalopas, J. L. Reno, and E. A. Shaner
A terahertz plasmon cavity detector
Appl. Phys. Lett. 97 , 193507 (2010).
50. P. T. Greenland, S. A. Lynch, A. F. G. van der Meer, B. N. Murdin, C. R. Pidgeon, B. Redlich, N. Q. Vinh, G. Aeppli
Coherent Control of Rydberg States in Silicon
Nature 465, 1057 (2010).
49. B. Wittmann, S. N. Danilov, S. A. Tarasenko, V. V. Bel’kov, E.G. Novik, H. Buhmann, C. Brune, L. W. Molenkamp, Z. D. Kvon, N. N. Mikhailov, S. A. Dvoretsky, N. Q.Vinh, A. F. G. van der Meer, B. Murdin, and S. D. Ganichev
Circular photogalvanic effect in HgTe/CdHgTe quantum well structures
Semicond. Sci. Technol. 25, 095005 (2010).
48. G. Davies, G. Liaugaudas, N. Q. Vinh, and K. Litvinenko
Three phonon decay mode of the 1136-cm-1 v3 vibration of oxygen in silicon
Phys. Rev. B 81, 033201 (2010).
47. G. Davies, K. K. Kohli, P. Clauws, and N. Q. Vinh
Decay mechanism of the v3 865 cm-1 vibration of oxygen in crystalline germanium
Phys. Rev. B 80, 113202 (2009).
46. R. P. Green, A. Tredicucci, N. Q. Vinh, B. Murdin, C. Pidgeon, H. E. Beere, and D. A. Ritchie
Gain recovery dynamics of a terahertz quantum cascade laser
Phys. Rev. B 80, 075303 (2009).
45. N. Q. Vinh, H. N. Ngo, and T. Gregorkiewicz
Photonic properties of Er-doped crystalline silicon
Review paper, The proceedings of the IEEE 97, 1269 (2009).
44. P. Rauter, T. Fromherz, N. Q. Vinh, G. Mussler, D. Grutzmacher, and G. Bauer
Continuous Voltage Tunability of Intersubband Relaxation Times in SiGe Quantum Well Structures
Phys. Rev. Lett. 102, 147401 (2009).
43. S. Minissale, N. Q. Vinh, A. F. G. van der Meer, M. S. Bresler, and T. Gregorkiewicz
Observation of THz transitions within the 4I15/2 ground multiplet of Er3+ ion in Si
Phys. Rev. B 79, 115324 (2009).
42. S. N. Danilov, B. Wittmann, P. Olbrich, W. Eder, W. Prettl, L. E. Golub, E. V. Beregulin, Z. D. Kvon, N. N. Mikhailov, S. A. Dvoretsky, V. A. Shalygin, N. Q. Vinh, A. F. G. van der Meer, B. Murdin, and S. D. Ganichev
Fast detector of the ellipticity of infrared and terahertz radiation based on HgTe quantum well structures
J. Appl. Phys. 105, 013106 (2009); e-print arXiv:0810.1205 (2008).
41. K. K. Kohli, N. Q.Vinh, P. Clauws, G.Davies
Strange lifetimes of the vibrations of interstitial oxygen in SiGe alloys
Physica B 404, 4689 (2009).
40. S. Minissale, N. Q. Vinh, and T. Gregorkiewicz
On relation between the 1.5 mm Er-related emission and 9 mm vibrational modes of oxygen in silicon
Physica E 41, 1052 (2009).
39. B. Wittmann, L. E. Golub, S. N. Danilov, J. Karch, C. Reitmaier, Z. D. Kvon, N. Q. Vinh, A. F. G. van der Meer, B. Murdin, and S.D. Ganichev
Resonant circular photogalvanic effect in GaN/AlGaN heterojunctions
Phys. Rev. B 78, 205435 (2008); e-print arXiv:0809.2718 (2008).
38. C. Balocco, M. Halsall, N. Q. Vinh, and A. M. Song
THz operations of asymmetric-nanochannel devices
J. Phys.: Condens. Matter 20, 384203 (2008).
37. N. Q. Vinh, P. T. Greenland, K. Litvinenko, B. Redlich, A. F. G. van der Meer, S. A. Lynch, M. Warner, A. M. Stoneham, G. Aeppli, D. J. Paul, C. R. Pidgeon and B. N. Murdin
Silicon as a model ion trap: Time domain measurements of donor Rydberg states
P. Natl. Acad. Sci. USA 105, 10649 (2008); e-print arXiv:0812.0148 (2008).
36. S. Minissale, N. Q. Vinh, W. de Boer, M. S. Bresler, and T. Gregorkiewicz
Microscopic evidence for role of oxygen in luminescence of Er3+ ions in Si: Two-color and pump-probe spectroscopy
Phys. Rev. B 78, 035313 (2008).
35. W. Weber, L. E. Golub, S. N. Danilov, J. Karch, C. Reitmaier, B. Wittmann, V. V. Bel’kov, E. L. Ivchenko, Z. D. Kvon, N. Q. Vinh, A. F. G. van der Meer, B. Murdin, and S. D. Ganichev
Quantum ratchet effects induced by terahertz radiation in GaN-based two-dimensional structures
Phys. Rev. B 77, 245304 (2008); e-print arXiv:0804.0342 (2008).
34. E. A. Zibik, T. Grange, B. A. Carpenter, R. Ferreira, G. Bastard, N. Q. Vinh, P. J. Phillips, M. J. Steer, M. Hopkinson, J. W. Cockburn, M. S. Skolnick, and L. R. Wilson
Intersublevel polaron dephasing in self-assembled quantum dots
Phys. Rev. B 77, Rapid com., 041307(R) (2008); e-print arXiv:0710.5095 (2007).
33. K. W. Jobson, J. -P. R. Wells, R. E. I. Schropp, N. Q. Vinh, J. I. Dijkhuis
Infrared transient grating measurements of the dynamics of hydrogen local mode vibrations in amorphous silicon-germanium
J. Appl. Phys. 103, 013106 (2008).
32. P. Aivaliotis, E. A. Zibik, L. R. Wilson, J. W. Cockburn, M. Hopkinson, N. Q. Vinh
Two photon absorption in quantum dot-in-a-well infrared photodetectors
Appl. Phys. Lett. 92, 023501 (2008).
31. K. W. Jobson, J. -P. R. Wells, N. Q. Vinh, P. J. Phillips, C. R. Pidgeon, and J. I. Dijkhuis
Mid-infrared pump–probe spectroscopy of Si–H stretch modes in porous silicon
Optical materials 30, 740 (2008).
30. I. Izeddin, M. A. J. Klik, N. Q. Vinh, M. S. Bresler, and T. Gregorkiewicz
Mid-infrared spectroscopy of the Er-related donor state in Si/Si:Er3+ nanolayers
Materials Science and Engineering B 146, 131 (2008).
29. S. Minissale, N. Q. Vinh, and T. Gregorkiewicz
Pump-probe investigations of THz transitions in Si/Si:Er3+ nanolayers
Materials Science and Engineering B 146, 160 (2008).
28. P. Rauter, T. Fromherz, N. Q. Vinh, B. N. Murdin, J. P. Phillips, C. R. Pidgeon, L. Diehl, G. Dehlinger, D. Grützmacher, Ming Zhao, Wei-Xin Ni, and G Bauer
Direct determination of ultrafast intersubband hole relaxation times in voltage biased SiGe quantum wells by a density matrix interpretation of femtosecond resolved photocurrent experiments
New journal of physics 9, 128 (2007).
27. I. Izeddin, M. A. J. Klik, N. Q. Vinh, M. S. Bresler, and T. Gregorkiewicz
Donor-State-Enabling Er-Related Luminescence in Silicon: Direct Identification and Resonant Excitation
Phys. Rev. Lett. 99, 077401 (2007).
26. N. Q. Vinh, S. Minissale, H. Vrielinck, and T. Gregorkiewicz
Concentration of Er3+ ions contributing to 1.5-um emission in Si/Si:Er nanolayers
Phys. Rev. B 76, 085339 (2007).
25. M. Califano, N. Q. Vinh, P. J. Phillips, Z. Ikoni´c, R. W. Kelsall, P. Harrison, C. R. Pidgeon, B. N. Murdin, D. J. Paul, P. Townsend, J. Zhang, I. M. Ross, and A. G. Cullis
Interwell relaxation times in p-Si/SiGe asymmetric quantum well structures: the role of interface roughness
Phys. Rev. B 75, 045338 (2007).
24. P. Rauter, T. Fromherz, G. Bauer, N. Q. Vinh, B. N. Murdin, J. P. Phillips, C. R. Pidgeon, L. Diehl, G. Dehlinger, and D. Grutzmacher
Direct monitoring of the excited state population in biased SiGe valence band quantum wells by femtosecond resolved photocurrent experiments
Appl. Phys. Lett. 89, 211111 (2006); (also selected by Editors for publication in the December 2006 issue of Virtual Journal of Utrafast Science).
23. K. W. Jobson, J.-P. R. Wells, N. Q. Vinh, P. J. Phillips, C. R. Pidgeon, and J. I. Dijkhuis
Vibrational relaxation pathways in porous silicon: A time-resolved infrared spectroscopic study
Phys. Rev. B 74, 165205, (2006).
22. K. K. Kohli, Gordon Davies, N. Q. Vinh, D. West, S. K. Estreicher, T. Gregorkiewicz, I. Izeddin, and K. M. Itoh
Isotope dependence of the lifetime of the 1136 cm-1 vibration of oxygen in silicon
Phys. Rev. Lett. 96, 225503 (2006).
21. K. K. Kohli, G. Davies, N. Q. Vinh, D. West, S. K. Estreicher, T. Gregorkiewicz, I. Izeddin, and K.M. Itoh
Isotope effects and temperature-dependence studies on vibrational lifetimes of interstitial oxygen in silicon
Nuclear Instruments and Methods in Physics Research B 253, 200 (2006).
20. Z. F. Krasilnik, B. A. Andreev, D. I. Kryzhkov, L. V. Krasilnikova, V. P. Kuznetsov, D. Y. Remizov, V. B. Shmagin, M. V. Stepikhova, A. N. Yablonskiy, T. Gregorkievicz, N. Q. Vinh, W. Jantsch, H. Przybylinska, V. Y. Timoshenko, and D. M. Zhigunov
Erbium doped silicon single- and multilayer structures for light-emitting device and laser applications
Journal of Materials Research 21, 574 (2006).
19. N. Q. Vinh, S. Minissale, B. A. Andreev, and T. Gregorkiewicz
The Auger process of luminescence quenching in Si/Si:Er multinanolayers
J. Phys.: Condens. Matter 17, S2191 (2005).
18. N. Q. Vinh, J. Phillips, Gordon Davies, and T. Gregorkiewicz
Time-resolved free-electron laser spectroscopy of a copper isoelectronic center in silicon
Phys. Rev. B 71, 085206 (2005).
17. N. Q. Vinh, xxx T. Gregorkiewicz
Erbium doped silicon single- and multilayer structures for LED and Laser applications
Materials Research Society Symposium Proceedings Vol. 866, V1.4.1 (2005).
16. N. Q. Vinh, H. Przybylinska, Z. F. Krasil’nik, and T. Gregorkiewicz
Optical properties of a single type of optically active center in Si/Si:Er nanostructures
Phys. Rev. B 70, 115332 (2004); (also selected by Editors for publication in the Virtual Journal of Nanoscale Science & Technology Vol. 10, (15) - October 11, 2004).
15. Gordon Davies, T. Gregorkiewicz, M. Zafar Iqbal, M. Kleverman, E. C. Lightowlers, N. Q. Vinh, and Mengxia Zhu
Optical properties of a silver-related defect in silicon
Phys. Rev. B 67, 235111 (2003).
14. N. Q. Vinh, H. Przybylinska, Z. F. Krasil’nik, and T. Gregorkiewicz
Microscopic structure of Er-related optically active centers in crystalline silicon
Phys. Rev. Lett. 90, 066401 (2003).
13. H. Przybylinska, N. Q. Vinh, B. A. Andreev, Z. F. Krasil’nik, and T. Gregorkiewicz
Microscopic structure of Er-related optically active centers in Si
Mat. Res. Soc. Symp. Proc. Vol. 770, I7.1.1, (2003).
12. N. Q. Vinh and T. Gregorkiewicz
Two-color mid-infrared spectroscopy of isoelectronic centers in silicon
Mat. Res. Soc. Symp. Proc. Vol. 770, I4.2.1, (2003).
11. N. Q. Vinh, M. Klik, B. A. Andreev, and T. Gregorkiewicz
Spectroscopic characterization of Er-1 center in selectively doped silicon
Mat. Sci. Eng. B-Solid 105, 150, (2003).
10. M. Forcales, M. A. J. Klik, N. Q. Vinh, J. Phillips, J-P. R. Wells, and T. Gregorkiewicz
Two-color mid-infrared spectroscopy of optically doped semiconductors
J. Lumin. 102-103, 85, (2003).
9. N. Q. Vinh, H. Przybylinska, Z. F. Krasil’nik, and T. Gregorkiewicz
Magneto-optical study of Er3+-related center in selectively doped Si:Er
Physica E 16, 544 (2003).
8. N. Q. Vinh, T. Gregorkiewicz, and K. Thonke
780-meV photoluminescence band in silver-doped silicon: Isotope effect and time-resolved spectroscopy
Phys. Rev. B 65, 033202 (2002).
7. O. B. Gusev, M. S. Bresler, P. E. Pak, I. N. Yassievich, M. Forcales, N. Q. Vinh, and T. Gregorkiewicz
Excitation cross-section of erbium in semiconductor matrices under optical pumping
Sol. St. Phen. 82-84, 651 (2002).
6. B. J. Pawlak, N. Q. Vinh, I. N. Yassievich, and T. Gregorkiewicz
Influence of p-n junction formation at a Si/Si:Er interface on low-temperature excitation of Er3+ ions in crystalline silicon
Phys. Rev. B 64, 132202 (2001).
5. O. B. Gusev, M. S. Bresler, P. E. Pak, I. N. Yassievich, M. Forcales, N. Q. Vinh, and T. Gregorkiewicz
Excitation cross section of erbium in semiconductor matrices under optical pumping
Phys. Rev. B 64, 075302, (2001).
4. N. Q. Vinh, M. A. J. Klik, T. Gregorkiewicz
Time-resolved photoluminescence study of Si:Ag
Physica B 308-310, 414 (2001).
3. N. Q. Vinh, I. N. Yassievich, and T. Gregorkiewicz
Erbium excitation across the bulk of silicon wafer: an effect of p–n junction at Si/Si:Er interface
Physica B 308-310, 357 (2001).
2. N. Q. Vinh, H. Przybylinska, Z. F. Krasil’nik, B. A. Andreev, T. Gregorkiewicz
Observation of Zeeman effect in photoluminescence of Er3+ ion imbedded in crystalline silicon
Physica B 308-310, 340 (2001).
1. M. Forcales, M. Klik, N. Q. Vinh, I. V. Bradley, J-P. R. Wells, T. Gregorkiewicz
Free-electron laser studies of energy transfer mechanisms in semiconductors doped with transition series ions
J. Lumin. 94-95, 243 (2001).