The Laboratory of Spectroscopy is one of the largest laboratories at the ISSP UL and it combines a variety of research methods related to optical, magnetic and electron spectroscopy.

The range of materials includes both bulk and polycrystals, glass, thin films, nanomaterials, liquids and gases. The available infrastructure includes both standard measurements (absorption, excitation, steady-state and time-resolved luminescence spectra) over a wide temperature range (6 K to 700 K) as well as vibrational (Raman and Fourier infrared) spectroscopy, ellipsometry, electron paramagnetic resonance , optically detectable magnetic resonance, subnanosecond luminescence characterization, thermostimulated luminescence measurement, ablation spectroscopy and X - ray photoelectron spectroscopy equipment.

The staff of the laboratory has extensive experience in the spectroscopic characterization of solid state materials and actively provides services to academic and industrial partners.

Scientific degree Name Surname Position Contact information
Dr.phys. Anatolijs Šarakovskis Head of the laboratory and Leading researcher Anatolijs.Sarakovskis
Dr.phys. Andris Antuzevičs Leading researcher Andris.Antuzevics
Dr.phys. George Chikvaidze Leading researcher Georgijs.Cikvaidze
Dr.phys. Andris Fedotovs Leading researcher Andris.Fedotovs
Dr.phys. Jevgēņijs Gabrusenoks Leading researcher Jevgenijs.Gabrusenoks
Dr.phys. Jurģis Grūbe Leading researcher Jurgis.Grube
Dr.phys. Vladimirs Pankratovs Leading researcher Vladimirs.Pankratovs
Profesors Dr.habil.phys. Uldis Rogulis Leading researcher Uldis.Rogulis
Dr.phys. Mārtiņš Rutkis Leading researcher Martins.Rutkis
Dr.habil.phys. Māris Spriņģis Leading researcher Maris.Springis
Dr.habil.phys. Baiba Bērziņa Leading researcher Baiba.Berzina
Dr.phys. Jeļena Butikova Leading researcher Jelena.Butikova
Dr.Phys. Guna Krieķe Leading researcher Guna.Krieke
Dr.habil.phys. Ņina Mironova-Ulmane Leading researcher Nina.Ulmane
Dr.phys. Laima Trinklere Leading researcher Laima.Trinklere
Mg. Guna Doķe Researcher Guna.Doke
Mg. Meldra Ķemere Researcher Meldra.Kemere
Dr. chem. Monika Skruodiene Researcher Monika.Skruodiene
Dr.phys. Edgars Elsts Researcher Edgars.Elsts
Dr.phys. Ramūnas Nedzinskas Researcher Ramunas.Nedzinskas Andrejs Pavļenko Researcher  
Mg. Maksims Poļakovs Researcher  
  Pāvels Rodionovs Researcher Pavels.Rodionovs
  Aleksej Žarkov Researcher  
Mg. Dace Ņilova Research Assistant Dace.Nilova
  Viktorija Pankratova Research Assistant Viktorija.Pankratova
Bc. Alise Podelinska Research Assistant Alise.Podelinska
Mg. Dzintars Bērziņš Research Assistant Dzintars.Berzins
Mg. Jēkabs Cīrulis Research Assistant Jekabs.Cirulis
Mg. Ingars Lukoševičs Research Assistant Ingars.Lukosevics
  Rihards Ruska Research Assistant Rihards.Ruska
  Aija Kalniņa Engineer Aija.Kalnina
Mg. Jānis Čipa Engineer Janis.Cipa
  Roberts Mārtiņš Kolbergs Engineer Roberts.Kolbergs
  Haralds Ozols Engineer Haralds.Ozols
  Čiro Federiko Tipaldi Engineer Ciro-Federiko.tipaldi
  Viesturs Tenis Vīksna Engineer Viesturs-Tenis.Viksna
  Kaspars Vītols Engineer Kaspars.Vitols
  Lūkass Šmeļkovs Laboratory Assistant Lukass.Smelkovs

Synthesis of rare-earth doped fluoride and oxyfluoride glass ceramics and nanocomposites.

Spectroscopic properties of rare-earth activated bulk materiāls are extensively studied many years.Based on these studies novel lasers, colour displays, light emiters and etc. are developed. Nanocomposites possess many intriguing properties which are not present in corresponding bulk materials. Therefore nanocomposites can be used in the fields, where the application of bulk materials is impossible, for example, in bionanotechnology, in nanophotonic, etc.In our laboratory the synthesis of nanoparticles is adopt and modified for the synthesis of rare-earth (RE) activated NaREF4 and BaREF4 nanocomposites. In addition it is working on a synthesis of new transparent oxyfluoride glass ceramics.

Studies of radiation energy transfer and relaxation mechanisms in doped nanocomposites by means of optical spectroscopy methods.

One of possible application of nanostructures is related with optical properties including luminescence of nanoparticles. In our lab photoluminescence spectra and kinetics of rare-earth activated complex fluoride nanostructures are studied in wide spectral and temperature range. Exciting radiation energy transfer and relaxation processes resulting in photoluminescence are studied. Much attention is paid for studies of upconversion processes in rare-earth doped nanofluorides which involve the absorption of multiple photons (usually IR) and subsequent emission of one single photon (VIS or UV).

Wide band gap materials

Research works by the Laboratory are focused on light-induced processes and defect luminescence in wide band gap solid state materials, such as III group nitrides, oxides and other materials available in the form of bulk and nanosize structures, in order to detect:

  • spectral characterization of materials containing absorption, photoluminescence and its excitation spectra ensuring spectral pasport of material;
  • defect-induced luminescence mechanisms, structure of luminescent defects and their behavior in materials;
  • processes of energy transfer between defects and host lattice;
  • influence of material size on luminescence properties (macrosize and nano-structures in 1D, 2D and 3D forms);
  • estimation of practical applications of materials for UV light dosimeters, gas sensors, UV and visible light emitters;
  • development of new materials for white light emitters with specific properties.

Research includes different spectral characterizations of materials in temperature range between 8 K and 300 K such as absorption/transmission spectra within the spectral range between 190 nm and 1100 nm, photoluminescence spectra (between 250 nm and 1500 nm) and its excitation spectra as well as optically and thermally stimulated luminescence and luminescence polarization measurements.

  • Magnetic resonance spectroscopy (EPR, ODMR);
  • Research of defect structure and luminescence mechanisms in fluoride, oxide crystals, oxyfluoride composites, and application of the materials.

Active projects:


Mechanochemistry for Sustainable Industry (2019-2023)


ZnMgO materials with tunable band gap for solar-blind UV sensors Implementation period (2019-2022)

European Regional Development Fund

Development of sustainable recycling technology of electronic scrap for precious and non-ferrous metals extraction (es-retech) (2021-2023)

Novel materials for development of all-optical temperature sensor (OPTSEN) (2020-2023)

Development of efficient clad-pumped fiber optical amplifiers for telecommunication systems (DOPAnT) (2019-2022)

Horizon 2020 - EUROfusion

WP PWIE (Plasma-Wall Interaction and Exhaust) SP X2: Optimization of laser-based surface analysis diagnostics (2021-2025)

Latvian Council of Science

Defect engineering of novel UV-C persistent phosphor materials (2022-2024)

Novel persistent luminescent material – red light emitter (2020-2022)

Up-conversion luminescence photolithography in organic compounds using nanoparticles/photoresist composition (2020-2022)


Growth and characterization of Ga2O3 and ZnMgO thin films for solar-blind ultraviolet applications (2020-2023)

Novel glasses and glass ceramics with different combinations of garnets doped with rare earth and 3d metal ions for temperature-resistant phosphors in high-power white LEDs – NOGACE (2020-2023)


Accomplished projects:

Baltic-German University Liaison Office Projects

Cooperation for development of luminescent oxyfluoride glass ceramics for white LEDs (2015)

Competence Centers

Investigation of the coating process parameters to provide high-quality lithium coatings and creation of lithium coating material prototype (2018)


Fast advanced Scintillator Timing (FAST) (2014-2018)

European Regional Development Fund

New luminescent materials for gas sensors and radiation convertors (2014-2015)

New Luminescent Materials for Energy Saving Light Sources (2010-2013)

European Regional Development Fund (LIAA administrated)

Inrared visualizer (2020)

European Social Fund

Experimental and theoretical investigation of technologically important materials (2013-2015)

Horizon 2020

The influence of the cell membrane asymmetry and curvature on the functioning of membrane proteins and the transport of therapeutic compounds (2016-2019)

ISSP UL project competition for students and young scientists

New materials for infrared light visualization (2016)

Latvia - France Program “OSMOZE”

Radiation induced processes in nitrides and other wide-gap materials (2003-2005)

Latvia – Lithuania-Taiwan Trilateral Scientific Cooperation Program

Nonpolar ZnO thin films: growth-related structural and optical properties (2014)

One-Dimensional Nanostructures of Ternary AlGaN and Metal Doped- Zinc Oxide with Tunable Bandgaps: Growth, Characterization and Optical Properties (2011-2013)

Latvian Council of Science​​​​​​​

Novel transparent nanocomposite oxyfluoride materials for optical applications (2018-2021)

Research of luminescence mechanisms and dosimeter properties in prospective nitrides and oxides using TL and OSL methods (2018-2021)

Spectroscopic studies of advanced dielectrics and wide-gap semiconductors with different local disorder (2013-2016)

Latvian-Belarusian cooperation programs in science and technology


Latvijas – Ukrainas divpusējās sadarbības programmas zinātnes un tehnoloģiju jomā

Fabrication, characterization and computer modelling of the nanostructured YAlO3:Mn ceramics for novel radiation dosimeters (2016-2018)

National Research Program

MultIfunctional Materials and composItes, photonicS and nanotechnology (IMIS2) (2014-2018)

Development of novel multifunctional materials, signal processing and information technologies for competitive knowledge-based products (2010-2013)

National Research Program of Latvia in Materialsciences (2010-2013)

For the firsts time transparent erbium doped oxyfluoride glassceramics containing only hexagonal NaYF4 nanocrystals has been prepared by melt-quenching and subsequent heat treatment of the precursor glass. Excitation energy relaxation peculiarities of the green and red luminescence creation in Er3+ activated oxyfluoride ceramics with hexagonal NaYF4 nanocrystalls are investigated. Novel Er3+ doped transparent glass ceramics containing hexagonal Na(Gd,Lu)F4 nanocrystals were prepared from oxyfluoride glasses. A strong deviation of rare earth ion content in fluoride nanocrystals in comparison to the base glass has been observed. Preferential incorporation of Gd3+ over Lu3+ ions in the fluoride lattice leads to the stabilization of hexagonal Na(Gd,Lu)F4 structure. A considerable enhancement of upconversion luminescence correlates with the formation of hexagonal solid solutions and is attributed to an efficient energy transfer between Er3+ ions.

  • Spectrometer (ANDOR) equipped with CCD camera (ANDOR) for traditional and up-conversion luminescence spectra (250 - 1000 nm) measurements at different temperatures (10 K – 300 K), excited by Xe lamp or laser diodes (445 nm, 808 nm and 980 nm, power up to 1 W).
  • EPR spectrometer: Microwave range 9 GHz (X-band), temperature range between 6.5 K and 300 K, X-ray excitation at 77 K and 300 K.
  • ODMR spectrometer: Magneto Optical Cryostat (manufactured by Oxford Instruments), microwave range Q (36-62 GHz), magnetic field up to 7 Tesla, measurement temperature from 1.5 to 300 K, excitation by X-rays at 4.2 K.

Measurements of Absorption spectra

SPECORD-210 (certified 2016): 1) absorption spectra in 190-1100 nm range 2) diffuse reflection spectra in 380 – 1100 nm range.

Measurement of Photoluminescence (PL) and Photoluminescence Excitation spectra (PLE). 2 homemade set-ups, containing 3 main units: i) sample holder – closed cycle He refrigerator CCS-100/204, Janis Res. Corp.; ii) luminescence excitation and; iii) luminescence registration units.

Luminescence excitation unit – 1) deuterium lamp DL- 400W; 2) deuterium lamp (Hamamatsu company), 3) xenon lamp 150W - (all lamps are used in conjugation with the monochromator MDR-2, LOMO) and 4) solid state laser 263 nm.

Luminescence registration units–1) monochromator Andor Shamrock SR-303i-B with 2 CCD cameras (spectral ranges: 250 nm – 800 nm and 600 nm – 1500 nm) and 2) monochromator SPM-2, Carl Zeiss with photoelectron tube H468-03 or H468-20 (230-600 nm, 400-900 nm, Hamamatsu company).

The absorption, PL and PLE can be measured at fixed temperatures in 8-300K (RT) temperature range.

Luminiscence polarization (250 – 1100 nm).

Absorption spectra equipment is available for common use. The equipment for PL and PLE measurements usually is in routine use by the laboratory’s staff, but it also can be used by other researchers on the pre-agreed basis.

Latvia :

  • R. Cimdins Riga Biomaterials Innovations and Development of Riga Technical University (Dr.L.Berzina-Cimdiņa, Dr. J. Locs).
  • Riga Technical University Institute of Inorganic Chemistry (Dr. J. Grabis).
  • Riga Technical University Faculty of material science and applied chemistry (prof. A. Medvids).
  • Institute of Technical Physics, Riga Technical University (Profs. A.Medvid, M.Knite)


  • Institute of Spectroscopy, Russian Academy of Sciences (prof. M. Popova).


  • University of bern department of chemistry and biochemistry (Dr. Karl Kramer).


  • South Westphalia University of Applied Sciences, Soest (Prof. Dr. habil. phys. S. Schweizer);
  • University of Paderborn (Prof. Emeritus, J.-M. Spaeth, Dr. habil. phys. S. Schweizer, Dr. habil. phys. S. Greulich-Weber).


  • National Institute of Materials Physics (NIMP), Bucharest-Magurele, Romania (Dr. M. Secu).


  • Lviv Polytechnic National University, Lviv (Dr. D. Sugak, Dr. Ya. Zhydashevskyy).
  • Institute of Physics of National Academy of Science of Ucraine, Kyiv (Drs. G. Dovbeshko, S. Yesylevskyy).
  • Materials Research Center, National Academy of Science of Ucraine, Kyiv (Prof. O.Gogotsi)


  • Institute of Applied Research, Department of Semiconductor Optoelectronics, Vilnius University (Dr. Patrik Scajev)
  • Optoelectronics department, Center for Physical Sciences and Technology (Dr. Ramunas Nedzinskas)


  • National Taiwan University, Taipei (Profs. Li-Chyong Chen, Kuei-Hsien Chen)
  • Department of Materials and Optoelectronic Science, National Sun Yat-Sen University, Kaohsiung (Prof. Mitch M.C. Chou, Liuwen Chang)


  • Universite de Franche-Comte, Besancon (Prof. C.Ramseyer, Dr. S. Foley)


  • Tartu University, Tartu (Prof. A.Freiberg).


Krieke, G., Antuzevics, A., Springis, M., Rogulis, U. Upconversion luminescence in transparent oxyfluoride glass ceramics containing   hexagonal NaErF4 (2019) Journal of Alloys and Compounds, 798, pp. 326-332. DOI: 10.1016/j.jallcom.2019.05.276

Antuzevics, A., Krieke, G., Pavlovska, E., Rogulis, U. Eu3+ ion distribution in oxyfluoride glass nanocomposites (2019) Journal of Non-  Crystalline Solids, 522, art. no. 119548. DOI: 10.1016/j.jnoncrysol.2019.119548

Trinkler, L., Trukhin, A., Cipa, J., Berzina, B., Korsaks, V., Chou, M.M.C., Li, C.-A. Spectral and kinetic characteristics of pyroelectric luminescence in LiGaO2 (2019) Optical Materials, 94, pp. 15-20. DOI: 10.1016/j.optmat.2019.05.014


M. Kemere, J. Sperga, U. Rogulis, G. Krieke, J. Grube, Luminescence properties of Eu, RE3+ (RE=Dy, Sm, Tb) co-doped oxyfluoride glasses and glass-ceramics, J. of Luminescence, 2017, vol.181, pp. 25-30, DOI: 10.1016/j.jlumin.2016.08.062.

Krieke, G., Sarakovskis, A., Ignatans, R., Gabrusenoks, J. Phase transitions and upconversion luminescence in oxyfluoride glass ceramics containing Ba4Gd3F17 nanocrystals.(2017) Journal of the European Ceramic Society, 37 (4), pp. 1713-1722.

Guna Krieke, Anatolijs Sarakovskis, Maris Springis. Upconversion luminescence of a transparent glass ceramics with hexagonal Na(Gd,Lu)F4 nanocrystals. Journal of Alloys and Compounds, (2017), 694 952e958.


E. Elsts, G. Krieke, U. Rogulis, K. Smits, A. Zolotarjovs, J. Jansons, A. Sarakovskis, K. Kundzins, Rare earth doped glass-ceramics containing NaLaFnanocrystals, Optical Materials 2016, vol. 59, p. 130-135, DOI: 10.1016/j.optmat.2016.01.005

U. Rogulis, Optical detection of paramagnetic centres: from crystals to glass-ceramics, 2016, Low temperature physics, 2016, v. 42, No. 7, pp. 689-693

A. Cvetkovs, O. Kiselova, U. Rogulis, V. Serga, R. Ignatans, Synthesis of ZnO and CdO-ZnO thin films by extraction–pyrolytic method, Latvian Journal of Physics and Technical Sciences, 2016, vol. 53, pp. 57–66, DOI: 10.1515/lpts-2016-0021

Oxygen influence on luminescence properties of rare-earth doped NaLaF4 A.Tuomela a,n, V.Pankratov, A.Sarakovskis, G.Doke, L.Grinberga, S.Vielhauer, M.Huttula. Journal of Luminescence, (2016), 179, pp.16–20.

Guna Krieke, Anatolijs Sarakovskis. Crystallization and upconversion luminescence of distorted fluoritenanocrystals in Ba2+containing oxyfluoride glass ceramics. Journal of the European Ceramic Society, (2016), 36, pp.1715–1722.

Jurgis Grube. Temperature influence on NaLaF4:Er3+ green luminescence. Journal of Luminescence, (2016), 179, pp. 107–113.

E. K. Yukhno, L. A. Bashkirov, P. P. Pershukevich, S. V. Slonskaya, N. A. Mironova- Ulmane, A. G. Sharakovskis. Excitation and photoluminescence spectra of solid solutions based on lanthanum indate LaInO3 of a perovskite structure doped with Nd3+ and Cr3+ ions. Glass Physics and Chemistry, (2016), v.42, pp. 379–385.

Sarakovskis, A., Grube, J., Strals, K., Krieke, G., Springis, M., Mironova-Ulmane, N., Skvortsova, V., Yukhno, E.K., Bashkirov, L.A. Temperature and impurity concentration effects on upconversion luminescence in LaInO3 doped with Er3+. Fizika Nizkikh Temperatur, (2016), v.42, pp. 733-737.

B.Berzina, V.Korsaks, L.Trinkler, A.Sarakovskis, J.Grube, S.Bellucci. Defect-induces blue luminescence of hexagonal boron nitride. Diamond and related materials. 68 (2016) 131-137.

L.Trinkler, A.Trukhin, B.Berzina, V.Korsaks, P.Ščaev, R.Nedzinskas, S.Tumėnas, M.M.C.Chou, L.Chang, C-A.Li. Luminescence properties of LiGaO2 crystal. Optical materials, 2016,


A. Fedotovs, Dz. Berzins, U. Rogulis, K. Smits, G. Doke, A. Medvids, P. Onufrijevs, Angular Dependence of Recombination Luminescence Detected EPR in ZnO Crystal, Physica scripta, 2015, vol. 90, No. 9, 094016. doi:10.1088/0031-8949/90/9/094016

A. Fedotovs, A. Antuzevics, U. Rogulis, M. Kemere, R. Ignatans, Electron paramagnetic resonance and magnetic circular dichroism of Gd3+ ions in the Oxyfluoride Glass-ceramics containing CaF2 nanocrystals, J. of Non-Crystalline solids, 2015, vol. 429, pp. 118-121.

A. Antuzevics, U. Rogulis, A. Fedotovs, Dz. Berzins, V. N. Voronov and J. Purans, EPR Study of Gd3+ local structure in ScF3 – crystal with negative thermal expansion coefficient, Physica Scripta, 2015, vol. 90, p. 115801.

Anatolijs Sarakovskis, Guna Krieke. Upconversion luminescence in erbium doped transparent oxyfluorideglass ceramics containing hexagonal NaYF4nanocrystals. Journal of the European Ceramic Society,(2015), 35 (13), pp. 3665-3671.

A. Sarakovskis, G. Krieke, G. Doke, J. Grube, L. Grinberga, M. Springis, Comprehensive study on different crystal field environments in highly efficient NaLaF4:Er3+ upconversion phosphor, Optical Materials 39 (2015), p. 90 – 96.

V. Korsaks. Hexagonal boron nitride luminescence dependent on vacuum level and surrounding gases, Materials Research Bulletin 70, (2015) 976- 979.


J. Grube, A. Sarakovskis, G. Doke, M. Springis, Impact of Er3+ Concentration on Luminescence in NaLaF4, Latvian Journal of Physics and Technical Sciences 51, 3 (2014), p. 42.

L. Trinkler, B.Berzina. Localised transitions in luminescence of AlN ceramics. Radiation Measurements, 71 (2014) 232-236.

L. Trinkler, B.Berzina. Recombination luminescence in aluminum nitride ceramics. Physica Status Solidi (B) Basic Research, 251 (2014) 542-548.

L.Trinkler, B.Berzina, E.Palcevskis. AlN Ceramics from nanosized plazma processed powder, its properties and application. Chapter in Book: Nitride ceramics. Combustion synthesis.(2014) 265-293.


U. Rogulis, E. Elsts, J. Jansons, A. Sarakovskis, G. Doke, A. Stunda, K. Smits, Cathodoluminescence of oxyfluoride glass-ceramics, Radiation Measurements, 2013, vol. 56, pp. 120-123; DOI 10.1016/j.radmeas.2012.12.020

Doke, G., Sarakovskis, A., Grube, J., Springis, M. Photoluminescence of neodymium and erbium doped NaLaF4 material (2013) Radiation Measurements, 56, pp. 27-30.

Rogulis, U., Elsts, E., Jansons, J., Sarakovskis, A., Doke, G., Stunda, A., Smits, K. Cathodoluminescence of oxyfluoride glass-ceramics (2013) Radiation Measurements, 56, pp. 120-123.

P.Ščajev, L.Trinkler, B.Berzina, E.Ivakin, K.Jarašiunas. Influence of boron on donor-acceptor pair recombination in type IIa HPHT diamonds. Diamond and Related Materterials 36 (2013) 35-43.


I. Brice, U. Rogulis, E. Elsts, J. GrūbePhotoluminescence of Eu and Ce activated oxyfluoride glass and glass ceramics. Latvian Journal of Physics and Technical Sciences, 2012, Nr. 6(I), p. 44.

A. Antuzevičs, A. Fedotovs, U. Rogulis, EPR spectrum angular dependences in LiYF4 crystal, Journal of Physics and Technical Sciences, 2012, Nr. 6(I), p. 49.

Dz. Berzins, A. Fedotovs, U. Rogulis, EPR hyperfine structure of radiation defect in oxyfluoride glass ceramics, Latvian Journal of Physics and Technical Sciences, 2012, Nr. 6(I), p. 55.

U. Rogulis, E. Elsts, J. Jansons, A. Sarakovskis, G. Doke, A. Stunda, K. Smits, Cathodoluminescence of oxyfluoride glass-ceramics, Radiation Measurements, 2013, vol. 56, pp. 120-123; DOI 10.1016/j.radmeas.2012.12.020

U. Rogulis, E. Elsts, J. Jansons, A. Sarakovskis, G. Doke, A. Stunda, K. Kundzins. Rare earth activated oxyfluoride glasses and glass-ceramics for scintillation applications. IEEE Transactions on Nuclear Science, 2012, Volume: 59, Issue: 5, Page(s): 2201 – 2206, Doi: 10.1109/TNS.2012.2212724

A. Sarakovskis, M. Voss, G. Doke, D. Jankovica, J. Grube. Synthesis of cubic and hexagonal NaYF4 :Er3+ (2012) IOP Conference Series: Materials Science and Engineering, 38, art. no. 012038;

R.Aleksiejūnas, P.Ščajev, S Nargelas, S.Miasojedovas, K.Jarašiūnas, L.Trinkler, J. Grigorjeva, B.Berzina, K.H.Chen, Y.T.Chen, M.W.Chen, and L.C.Chen. Carrier dynamics in epilayers and nanocolumns of ternary AlGaN with a tunable bandgap. IOP Conf. Series: Materials Science and Engineering 38 (2012) 012054.

L. Trinkler, B. Berzina, Z. Jevsjutina, J. Grabis, I. Steins and C. J. Baily. Photoluminescence of Al2O3 nanopowders of different phases. Optical Materials 34 (2012) 1553–1557;

V. Korsaks, B. Berzina, L. Trinklere. Influence of air, oxygen, nitrogen and argon gases on 400 nm luminescence in hexagonal boron nitride. Latvian journal of physics and technical science 49 (2012) 57-62.

T.Glaskova, M.Zarelli, A.Anishkevich, M.Giordano, L.Trinkler, B.Berzina , Quantitative optical analysis of filler dispersion degree in MWCNT-epoxy nanocomposite. Composites Science and Technology 72, 4 (2012).


A. Fedotovs, Dz. Berzins, O. Kiselova, A. Sarakovskis and U. Rogulis. Analysis of Mn2+ EPR spectral shapes for studies of the oxyfluoride glass ceramics. IOP Conf. Ser.: Mater. Sci. Eng., 2011, vol. 23, 012018, doi:10.1088/1757-899X/23/1/012018.

J. Grube, G. Doke, M. Voss, A. Sarakovskis, M. Springis. Multicolor up-conversion luminescence in Rare-Earth doped NaLaF4 (2011) IOP Conference Series: Materials Science and Engineering, 23 (1), art. no. 012004;

A. Sarakovskis, M. Voss, G. Doke, J. Grube, M. Springis. Novel synthesis of up-conversion phosphor based on rare-earth doped NaLaF4 (2011) IOP Conference Series: Materials Science and Engineering, 23 (1), art. no. 012003;

L.Trinkler and B.Berzina. Luminescence properties in AlN ceramics and its potential application for solid state dosimetry. pp. 59-82. A chapter in book Advances in Ceramics - Characterization, 82 Raw Materials, Processing, Properties, Degradation and Healing. ISBN 978-953-307-504-4, Hard cover, 370 pages, Publisher: InTech, Publication date: August 2011.

L. Trinkler, B. Berzina, UV radiation induced processes in AlN and its potential application for solid state dozimetry. Conference proceedings ”Current challenges in radiation protection”, Reykjavik, (2011).

V. Korsaks, B. Berzina, L.Trinklere, Low temperature 450 nm luminescence of hexagonal boron nitride, Latvian Journal of Physics and Technical Science, 1 (2011).

L.Trinkler and B.Berzina, Luminescence properties in AlN ceramics and its potential application for solid state dosimetry, A chapter in book Advances in Ceramics - Characterization, 82 Raw Materials, Processing, Properties, Degradation and Healing. ISBN 978-953-307-504-4, 370 pages, Publisher: InTech, (2011).

L.Trinkler, B.Berzina, D.Jakimovica, J.Grabis, I.Steins, Peculiarities of photoluminescence of Al2O3 bulk and nanosize powders at low temperature, Optical materials, 33 (2011).


A. Fedotovs, U. Rogulis, A. Sarakovskis, L. Dimitrocenko, EPR of radiation defcts in lithium-oxyfluoride glass ceramics. J. of Physics: Conference Series, 249 (2010)

A. Fedotovs, Dz. Berzins, A. Sarakovskis, U. Rogulis, G. Doke, EPR studies of the oxyfluoride glass ceramics using Mn2+ as a paramagnetic probe. IOP Conference Series: Materials and Engineering, 15 (2010)

E. Elsts, U. Rogulis, J. Jansons, A. Sarakovskis, Cathodoluminescence of terbium and ytterbium activated oxyfluoride glasses and glass ceramics. Latvian Journal of Technical Sciences, 5, pp. 48 (2010)

A. Fedotovs, U. Rogulis, A. Sarakovskis, L. Dimitrocenko, EPR of radiation defcts in lithium-oxyfluoride glass ceramics. J. of Physics: Conference Series, 249 (2010);

A. Fedotovs, Dz. Berzins, A. Sarakovskis, U. Rogulis, G. Doke, EPR studies of the oxyfluoride glass ceramics using Mn2+ as a paramagnetic probe. IOP Conference Series: Materials and Engineering, 15 (2010);

E. Elsts, U. Rogulis, J. Jansons, A. Sarakovskis, Cathodoluminescence of terbium and ytterbium activated oxyfluoride glasses and glass ceramics. Latvian Journal of Technical Sciences, 5, pp. 48 (2010);

A. Sarakovskis, J. Grube, G. Doke, M. Springis. Selective excitation of up-conversion luminescence by Yb3+-Er3+ energy transfer in glass and crystalline phase of oxyfluoride glass ceramics (2010) Optical Materials, 32 (8), pp. 832-835;

I. Tale, L. Dimitrocenko, P.Kulis, G. Marcins, A. Sarakovskis, A.Voitkans, Localization dynamics of exciton luminescence in InxGa1-xN epitaxial films. 11th Europhysical Conference on Defects in Insulating Materials (EURODIM2010) IOPPublishing, IOP Conf. Series: Materials Science and Engineering, 15 012059 (2010);

A. Sarakovskis, J. Grube, G. Doke, and M. Springis, Excited state absorption and energy transfer mechanisms of up-conversion luminescence in Er3+ doped oxyfluoride glass ceramics at different temperatures. J. Luminescence, 130, pp.805-811 (2010);

L.Trinkler, B.Berzina, D.Jakimovica, J.Grabis, I.Steins, UV-light induced luminescence process in Al2O3 bulk and nanosize powders, Optical Materials 32 (2010).


U. Rogulis, R.C. Baetzold, J.-M. Spaeth, Luminescence-detected EPR of oxygen-vacancy complexes in CaF2, Physica status solidi (b), 246, (2009).

A.N. Trukhin, J. Teteris, A. Fedotov, D.L. Griscom and G. Buscarino, Photosensitivity of SiO2–Al and SiO2–Na glasses under ArF (193 nm) laser, Journal of Non-Crystalline Solids, 355, (2009).

J.Grabis, I. Steins, A.Patmalnieks, B.Berzina and L.Trinklere, Preparation and processing of doped AlN nanopowders, Estonian Journal of Engineering 15, 4 (2009).

Y.F. Zhukovskii, S. Bellucci, S. Piskunov, L. Trinkler, B. Berzina, Atomic and electronic structure of single-walled BN nanotubes containing N vacancies as well as C and O substitutes of N atoms, European Physical Journal B 67 (2009).

Y.F. Zhukovskii, S. Piskunov, N. Pugno, B. Berzina, L. Trinkler, S. Bellucci, Ab initio simulations on the atomic and electronic structure of single-walled BN nanotubes and nanoarches, Journal of Physics and Chemistry of Solids 70 (2009).

B. Berzina, L. Trinkler, D. Jakimovica, V. Korsaks, J. Grabis, I. Steins, E. Palcevskis, S. Bellucci, L.-C. Chen, S. Chattopadhyay, K. Chen, Spectral characterization of bulk and nanostructured aluminum nitride, Journal of Nanophotonics 3, 1 (2009).


B. Henke, U. Rogulis, S. Schweizer, Structure sensitive investigations on luminescence centres in Mn-activated LiBaF3 dosimeters, Radiation Measurements, 43, (2008).

R.T. Williams, K.B. Ucer, D.L. Carroll, B. Berzina, L. Trinkler, V. Korsak, R. Krutohvostov, Photoluminescence of self-trapped excitons in boron nitride nanotubes, Journal of Nanoscience and Nanotechnology 8, 1-5 (2008).

E.M. Shishonok, L. Trinkler, S.V. Leonchik, B. Berzinya, Luminescence of thulium-activated cubic boron nitride, Journal of Applied Spectroscopy 75, 4 (2008).

L. Trinkler, B. Berzina, D. Kasjan, L.-Ch. Chen, Luminescence processes induced by UV radiation in AlN nanotips and nanorods, Radiation Measurements 43 (2008).


A. Fedotovs, E. Elsts, U. Rogulis, A. Gulans, I.Tale, M. Nikl, N. Ichinose, K. Shimamura, EPR Hyperfine Structure of F-type Centres in Pure LiBaF3 Crystal, Physica status solidi (c), 4/3, (2007).

L. Dimitrocenko, U. Rogulis, A. Veispals, M. Springis, P. Kulis, A. Fedotovs, and A. Mishnev, Luminescence of Ce-doped borate-oxyfluoride glass ceramics, Physica status solidi (c), 4/3, (2007).

B. Henke, U. Rogulis and S. Schweizer, Optical and Electron Paramagnetic Resonance Studies on Radiation Defects in Mn-activated RbCdF3, Physica status solidi (c), 4/3, (2007).

S. Schweizer, B. Henke, U. Rogulis, and W. M. Yen, Recombination processes in rare-earth doped MAl2O4 (M = Ca, Sr) persistent phosphors investigated by optically-detected magnetic resonance, Physica status solidi (a), 4/3, (2007).

S. Schweizer, B. Henke, U. Rogulis, W.M. Yen, Optically-detected magnetic resonance investigations of recombination processes in undoped and rare-earth doped MAl2O4 (M = Ca, Sr) persistent phosphors, Applied Physics Letters, 90, (2007).

A. Sarakovskis, L. Dimitrocenko, A. Misnevs, U. Rogulis, M. Springis, Up-conversion process in Erbium doped lithium fluoride bulk crystal, lithium borate oxyfluoride glass and glass ceramics, J. of Physics: Conference series, 93, (2007).

L. Trinkler, B. Berzina, A. Auzina, M. Benabdesselam, P. Lacconi, Use of aluminum nitride for UV radiation dosimetry, Nuclear Instruments and Methods in Physics Research A 580 (2007).

B. Berzina, L. Trinkler, J. Grabis, I. Steins, Photoluminescence in AlN: macro-size and nano- powder, Physica Status Solidi (c) 4, 3 (2007).


B. Henke, U. Rogulis, S. Schweizer, Optically detected magnetic resonance investigation of a luminescent oxygen-vacancy complex in LiBaF3, Journal of Physics: Condensed Matter, 18, (2006).

A.Fedotovs, E.Elsts, U.Rogulis, I.Tale, M.Nikl, N.Ichinose, K.Shimamura, EPR of F type centres in LiBaF3, Proceedings of the international Conference on Inorganic Scintillators and their Industrial Applications SCINT2005, Alushta, Ukraine, (2006).

B. Henke, U. Rogulis, and S. Schweizer, Luminescent oxygen-vacancy complex in Mn-doped LiBaF3 investigated by optically detected magnetic resonance, Proceedings of the international Conference on Inorganic Scintillators and their Industrial Applications SCINT2005, Alushta, Ukraine, (2006).

A. Fedotovs, L. Dimitrocenko, U.Rogulis, EPR of radiation defects in LiYF4 crystal, Proceedings of the international Conference on Inorganic Scintillators and their Industrial Applications SCINT2005, Alushta, Ukraine, (2006).

U. Rogulis, A. Veispals, L. Dimitrocenko, M. Springis, P. Kulis, A. Fedotovs, Optical properties of Ce-doped oxifluoride composites, Latvian Journal of Physics and Technical Sciences, 2 (2006).

S. Schweizer, B. Henke, U. Rogulis, and W. M. Yen, Recombination processes in rare-earth doped MAl2O4 (M = Ca, Sr) persistent phosphors investigated by optically-detected magnetic resonance, Physica status solidi (c), (2006).

S. Schweizer, B. Henke, U. Rogulis, W.M. Yen, Optically-detected magnetic resonance investigations of recombination processes in undoped and rare-earth doped MAl2O4 (M = Ca, Sr) persistent phosphors, Applied Physics Letters, (2006).

S. Schweizer, B. Henke, U. Rogulis, W.M. Yen, Magneto-optical resonance investigations on Eu- and Nd-/Dy-codoped CaAl2O4 and SrAl2O4 single crystals, "Proceedings of the First International Symposium on Persistent Phosphors", Quebec City, May 2005, Proceeding 06, (the Electrochemical Society, Pennington 2006).

B. Berzina, L. Trinkler, V. Korsak, R. Krutohvostov, D.L. Carrol, K.B. Ucer, R.T. Williams, Exciton luminescence of boron nitride nanotubes and nano-arches, Physica Status Solidi (b) 243, 14 (2006).


S. Schweizer, B. Henke, U. Rogulis, W.M. Yen, Magneto-optical resonance investigations on Eu- and Nd-/Dy-codoped CaAl2O4 and SrAl2O4 single crystals, in: Science and Technology of Dielectrics in Emerging Fields -and- Persistent Phosphors (PV 2005-13), pp. 191-198. Published by: The Electrochemical Society, 2006. Editors: Worhoff, Misra, Mascher, Sundaram, Yen, and Capobianco ISBN: 1-56677-511-6.

A. Fedotovs, U. Rogulis, Perturbed Cd centre in BaF2 crystal, Latvian Journal of Physics and Technical Sciences, 3, (2005).

A. Sharakovsky, M. Springis, U. Rogulis, I. Tale, Photostimulated recombination processes in X-ray irradiated CsCdF3:Mn crystals, Proceedings of SPIE: 4th International Conference on Advanced optical Materials (AOMD-4), 5946, (2005).

M. Springis, A. Sharakovsky, I. Tale, U. Rogulis, X-irradiation induced photo- and thermostimulated luminescence of CsCdF3:Mn crystals, Physica status solidi (c), 2, (2005).

E. Elsts, U. Rogulis, EPR hyperfine structure of the Mo-related defect in CdWO4, Physica status solidi (c), 2, (2005).

M. Secu, U. Rogulis, B. Henke, S. Schweizer, J.-M. Spaeth, Optical and magneto-optical studies on Mn-activated LiBaF3, Physica status solidi (c), 2, (2005).


I. Tkach, U. Rogulis, S. Greulich-Weber, J.-M. Spaeth, W-Band, Fabry-Perot microwave resonator for optically detected electron paramagnetic resonance and electron nuclear doeuble resonance of paramagnetic defects in solids, Review of Scientific Instruments, 75, (2004).

European patent White light emitter compound material for luminescent lamps and method for making same. European patent specification number EP 2883933 B1; Date of publication and mention of the grant of the patent 01.02.2017. Authors: B.Berzina, V.Korsaks, L.Trinkler, M.Knite, J.Grabis.

European patent Oxygen gas sensor. European patent application number EP 3121589 A1; Date of publication 25.01.2017. Authors: B.Berzina, L.Trinkler, V.Korsaks, J.Grabis.