About
Interests:
- study of the recombination processes in modern electronic devices;
- study of carrier transport phenomena;
- study of radiation nanoclusters;
- spectroscopy of defects and creation of spectroscopy techniques based on photoelectrical phenomena;
- search of radiation hard materials and development of radiation tolerant structures;
- engineering of radiation defects and radiation technologies for production of electronic devices;
- creation of new measurement technologies;
- technologies and instruments for the remote in situ measurements in harsh irradiation environments;
- modelling and simulations of the modern device structures;
- simulation of spectral characteristics of defects
Materials and structures under investigation:
- semiconductors of various technologies: Si, Ge, Si-Ge, GaAs, GaN, CdS, ZnSe, diamond, etc.;
- organic and polymeric materials: alanine, PEN, etc.;
- structures of devices and detectors: solar cells, LEDs, power PIN diodes and thyristors, CERN particle detectors
Measurement techniques:
- microwave absorption and reflection transient techniques;
- infrared absorption transient techniques;
- capacitance and current deep level transient spectroscopy (DLTS);
- electron paramagnetic resonance (EPR) spectroscopy;
- infrared spectroscopy (IRS) of vibrational modes;
- small harmonic test signal and pulsed capacitance spectroscopy (LRC/BELIV);
- photo-ionisation pulsed spectroscopy (PIPS); Measurement technologies:
- technology of the in situ analysis of evolution of radiation defects;
- technology of lateral and cross-sectional scans of defects distribution;
- technology of pulsed thermal, photo-ionisation and capacitance spectroscopy;
- technology of profiling of injected charge drift current transients;
- technology of the in situ analysis of evolution of luminescence and photoconductivity during irradiation by various high energy particles.
Researchers
|
Dr. Tomas Čeponis Senior researcher Saulėtekis av. 3, room B229 Phone: +370 5 2234486 |
Prof. Eugenijus Gaubas Chief researcher Saulėtekis av. 3, room A202 Phone: +370 5 2234469 |
Prof. Juozas V. Vaitkus Professor emeritus Saulėtekis av. 3, room B233
|
 Dr. Jevgenij Pavlov Researcher Saulėtekis av. 3, room B204 Phone: +370 5 2234487 |
 Dr. Vytautas Rumbauskas Researcher Saulėtekis av. 3, room B204 Phone: +370 5 2234487 |
Dr. Algirdas Mekys Senior researcher
|
 Dr. Laimonas Deveikis Researcher Saulėtekis av. 3, room B204 Phone: +370 5 2234487 |
Facilities
EPR and microscopy laboratory B206
Equipment:
-
EPR scanner BRUKER-E-SCAN
-
Dosimetry in the range of 1Gy -200 kGy
Laboratory of microwave spectroscopy B207
VU proprietary instrument for in situ dosimetry and defect spectroscopy VUTEG-3:
-
apšvitų hadronais įtėkio matavimams 1010-1016 cm-2 intervale;
-
for research of the evolution of radiation defects;
-
compatible with vacuum irradiation chamber;
-
for dosimetry of the spallator neutrons.
VU proprietary scanner VUTEG-04-CERN:
-
carrier lifetime scanner over 120x120 mm2 area;
-
scanner of the carrier lifetime and depth-distribution of defects with precision of 2 µm;
-
the range of the stabilized temperature 4°– 25° C;
-
suppression of carrier trapping component by cw IR illumination;
-
imaging of the distribution of radiation defects and irradiation fluences.
VU proprietary dosimeter VUTEG-5-AIDA, installed at CERN:
-
the range of hadron fluences 1010-1016 cm-2;
-
for research of the evolution of radiation defects;
-
separation of the carrier trapping component by cw IR illumination;
-
profiling of dose distribution within Si dosimeters.
VU proprietary instrument for pulsed spectroscopy of thermal and photo-ionization VUTEG-6:
-
contactless measurements of carrier emission lifetime;
-
for research of the evolution of radiation defects;
-
separation of the carrier trapping component by cw IR illumination
-
temperature range 80 – 400° K
Laboratory of the infrared spectroscopy B208
VU proprietary instrument for profiling of carrier drift transients:
-
for analysis of the carrier drift components;
-
measurement of carrier drift currents and transit times;
-
using surface scanning regime;
-
sing wafer edge scanning regime;
-
discretely variable excitation wavelengths in the range of 1062 –354 nm.
VU proprietary scanner of simultaneous spectroscopy of time-resolved luminescence and microwave-probed photoconductivity
Laboratory of deep level spectroscopy B208
VU proprietary profiler of the BELIV transients:
- pulsed barrier evaluation (BELIV) technique for spectroscopy of junction structures Si,Ge, GaAs, GaN, Cu-CdS;
- edge scanning of BELIV transients;
- discretely variable excitation wavelengths in the range of 1062 –354 nm;
- temperature range 90 – 350° K.
DLTS spectrometer HERA- DLTS System FT 1030:
- recording of the C-I-O-DLTS spectra;
- temperature range 10 – 450° K;
- pulsed lasers for carrier injection using 1062 and 351 nm wavelengths;
- advanced instruments for spectra analysis.
Projects
Ongoing:
Centre of technologies for remote and contactless detection of the ionizing radiations
Number: 01.2.2-CPVA-K-703-02-0002
Head: E. Gaubas
Duration: 2018 - 2021
Funding: 982 900 €
Agency: CPVA
Įvykdyti:
Development of the MOCVD GaN based technology for fabrication of position and spectrum selective detectors of ionizing radiations
Number: LAT 01/2016
Head: E. Gaubas
Duration : 2016 - 2018
Funding: 299 722 €
Agency: LMT
Advanced European Infrastructures for Detectors at Accelerators
Number: H2020 WP15 654168
Head: J. Vaitkus
Duration: 2015 - 2018
Funding: 40 000 €
Agency: EUC
LAMETECH INFRASTRUKTŪRA
Number: VP2-1.1-ŠMM-04-V-02-002
Head: resp. lead. E. Gaubas
Duration: 2014 - 2015
Funding: 250 000 €
Agency: LMT
Radiation nanoclusters in Si and GaN
Number: VP1-3.1-ŠMM-07-K-03-010
Head: J. Vaitkus
Duration: 2013 - 2015
Funding: 979 000 Lt
Agency: LMT
In situ and ex situ evolution of radiation defects in diamond and GaN materials
Number: MIP060/2013
Head: E. Gaubas
Duration: 2013 - 2015
Funding: 313 700 Lt
Agency: LMT
Advanced European Infrastructures for Detectors at Accelerators
Number: FP7-AIDA 262025 WP8.3
Head: resp. lead. E. Gaubas
Duration: 2011 - 2014
Funding: 42 000 €
Agency: EUC
Publications
2021
V. Kažukauskas, V. Janonis , V. Vertelis, „Energy band-gap inhomogeneities and defect states affecting carrier transport at low temperatures in Thallium Bromide“, Optical Materials Vol. 118, p. 111259 (1-8), 2021
L. Deveikis, J.V. Vaitkus, T. Čeponis, M. Gaspariūnas, V. Kovalevskij, V. Rumbauskas, E. Gaubas, „Profiling of proton beams by fluence scanners“, Lithuanian Journal of Physics Vol. 61, No. 2, p. 75-83, 2021
E. Gaubas, T. Čeponis, L. Deveikis, J. Pavlov, V. Rumbauskas, Patent: „HYBRID MULTI-LAYER SENSOR AND METHOD FOR LARGE FLUENCE DOSIMETRY AND FLUXIMETRY“, application No.: 21 165 145.0, submission data: 2021 03 26.
2020
E. Gaubas, T. Čeponis, L. Deveikis, V. Kalesinskas, G. Kreiza, T. Malinauskas, J. Pavlov, V. Rumbauskas, A. Mychko, V. Ivanov, “Study of the electrical characteristics of CdZnTe Schottky diodes”, Materials Science in Semiconductor Processing Vol. 105, p. 104705 (1-11), 2020.
J. Pavlov, T. Čeponis, L. Deveikis, V. Rumbauskas, G. Tamulaitis, E. Gaubas, “Modification of characteristics of AlGaN photodiodes by 1.6 MeV proton irradiation”, Journal of Instrumentation, Vol. 15, p. C01026 (1-9), 2020.
T. Heikkinen, J. Pavlov, T. Čeponis, E. Gaubas, M. Zając, F. Tuomisto, “Effect of Mn and Mg dopants on vacancy defect formation in ammonothermal GaN”, Journal of Crystal Growth, Vol. 547, p. 125803 (1-5), 2020.
2019
E. Gaubas, P. Baronas, T. Čeponis, L. Deveikis, D. Dobrovolskas, E. Kuokstis, J. Mickevičius, V. Rumbauskas, M. Bockowski, M. Iwinska, T. Sochacki, Study of spectral and recombination characteristics of HVPE GaN grown on ammono substrates, Mat. Sc. Semicond. Process. 91 (2019) 341–355.
E. Gaubas, T. Čeponis, D. Meškauskaite, J. Mickevičius, J. Pavlov, V. Rumbauskas, R. Grigonis, M. Zajac, R. Kucharski, Pulsed photo-ionization spectroscopy of traps in as-grown and neutron irradiated ammonothermally synthesized GaN, Scientific Reports 9 (2019) 1473.
E. Gaubas, T. Čeponis, L. Deveikis, D. Dobrovolskas, V. Rumbauskas, M. Viliūnas, Room-temperature infrared photoluminescence in GaN doped with various impurities, Optical Materials 94 (2019) 266–271.
T. Ceponis, K. Badokas, L. Deveikis, J. Pavlov, V. Rumbauskas, V. Kovalevskij, S. Stanionyte, G. Tamulaitis, E. Gaubas, Evolution of scintillation and electrical characteristics of AlGaN double-response sensors during proton irradiation, Sensors 19 (2019) 3388. doi:10.3390/s19153388
E. Gaubas, T. Ceponis, L. Deveikis, D. Dobrovolskas, V. Kalesinskas, J. Pavlov, V. Rumbauskas, and A. Mychko, Spectroscopy of defects in CdZnTe structures, Semicond. Sci. Technol. 34 (2019) 115012
L.F. Makarenko, S.B. Lastovski, H.S. Yakushevich, E. Gaubas, J. Pavlov, V.V. Kozlovski, M. Moll, I. Pintilie, Formation of a bistable interstitial complex in irradiated p-type silicon, Phys. Status Solidi A-Appl. Mat. 216 (2019) 1900354.
D. Dobrovolskas, G. Tamulaitis, E. Gaubas, M. Korjik, GAGG:Ce scintillation fibers for high energy physics applications, J. Instrum. 14 (2019) P06031.
E. Gaubas, T. Ceponis, L. Deveikis, V. Kalesinskas, G. Kreiza, T. Malinauskas, J. Pavlov, V. Rumbauskas, A. Mychko, V. Ivanov, Study of the electrical characteristics of CdZnTe Schottky diodes, Mat. Sc. Semicond. Process. 105 (2020) 104705.
J. Pavlov, T. Ceponis, T. Heikkinen, V. Rumbauskas, L. Deveikis, J. Raisanen, G. Tamulaitis, F. Tuomisto, E. Gaubas, Spectroscopy of defects in neutron irradiated ammono-thermal GaN by combining photo-ionization, photoluminescence and positron annihilation techniques, Lith. Journ. Phys., 59, (2019). 179–191.
J. Pavlov, T. Ceponis, L. Deveikis, V. Rumbauskas, G. Tamulaitis, and E. Gaubas, Modification of characteristics of AlGaN photodiodes by 1.6 MeV proton irradiation, JINST, 074P (2019) 1019.
V. Kazukauskas, G.L.Myronchuk,.; O.V.Parasyuk, et al. Photoconductivity of Tl1-xIn1-xSnxSe2 single crystals at low temperatures, Proceedings of the romanian academy series a-mathematics physics technical sciences information science, 20 (2019) 243 -249.
2018
E.Gaubas, T.Ceponis, L.Deveikis, D.Meskauskaite, J.Pavlov, V.Rumbauskas, J.Vaitkus, M.Moll, F.Ravotti, “Anneal induced transformations of defects in hadron irradiated Si wafers and Schottky diodes”, Materials Science in Semiconductor Processing 75, 157–165 (2018).
E. Gaubas, T. Ceponis, J. Mickevicius, J. Pavlov, V. Rumbauskas, M. Velicka, E. Simoen, and M. Zhao, “Pulsed photo-ionization spectroscopy in carbon doped MOCVD GaN epi-layers on Si”, Semicond. Sci. Technol. 33, 075015 (2018).
E. Gaubas, T. Čeponis, D. Dobrovolskas, J. Mickevičius J. Pavlov, V. Rumbauskas, J.V. Vaitkus, N. Alimov, and S. Otajonov, “Study of polycrystalline CdTe films by contact and contactless pulsed photo-ionization spectroscopy”, Thin Solid Films 660, 231–235 (2018).
2017
E. Gaubas, T. Ceponis, L. Deveikis, D. Meskauskaite, S. Miasojedovas, J. Mickevicius, J. Pavlov, K. Pukas, J. Vaitkus, M. Velicka, M. Zajac, and R. Kucharski, “Study of neutron irradiated structures of ammonothermal GaN”, J. Phys. D: Appl. Phys. 50, 135102 (2017).
E. Gaubas, T. Ceponis, D. Meskauskas, J. Pavlov, A. Zukauskas, V. Kovalevskij,V. Remeikis, “In situ characterization of radiation sensors based on GaN LED structure by pulsed capacitance technique and luminescence spectroscopy”, Sens. & Act. A 267, 194–199 (2017).
E. Gaubas, T. Ceponis, D. Dobrovolskas, T. Malinauskas,D. Meskauskaite, S. Miasojedovas, J. Mickevicius, J. Pavlov,V. Rumbauskas, E. Simoen, and M. Zhao, “Study of recombination characteristics in MOCVD grown GaN epi-layers on Si”, Semicond. Sci. Technol. 32, 125014 (2017).
2016
E. Gaubas, T. Ceponis, D. Meskauskaite, R. Grigonis, and V. Sirutkaitis, “Spectroscopy of defects in HPHT and CVD diamond by ESR and pulsed photo-ionization measurements”, J. Instrum. 11, C01017 (2016).
E. Gaubas, T. Ceponis, J.V. Vaitkus, V. Fadeyev, S. Ely, Z. Galloway, H.F.-W. Sadrozinski, M. Christophersen, B.F. Phlips, I. Gorelov, M. Hoeferkamp, J. Metcalfe, and S. Seidel, “Study of surface recombination on cleaved and passivated edges of Si detectors”, Semicond. Sci. Technol. 31, 035003 (2016).
E. Gaubas, T. Ceponis, D. Meskauskaite, and E. Simoen, “Comparative study of current transients in HPHT and CVD diamond capacitor-sensors”, ECS J. Solid State Sci. Technol. 5 (2016).
E. Gaubas, E. Simoen, and J. Vanhellemont, “Review-Carrier lifetime spectroscopy for defect characterisation in semiconductor materials and devices”, ECS J. Solid State Sci. Technol. 5, P3108-P3137 (2016).
E. Gaubas, T. Ceponis, E. Kuokstis, D. Meskauskaite, J. Pavlov, and I. Reklaitis, “Study of charge carrier transport in GaN sensors”, Materials 9, 293 (2016).
V. Rumbauskas, D. Meskauskaite, T. Ceponis, E. Gaubas, “Anneal induced transforms of radiation defects in heavily electron irradiated Si diodes”, J. Instrum. 11, P09004 (2016).
2015
E.Gaubas, T. Ceponis, and J. Pavlov, “Pulsed current signals in capacitor type particle detectors”, JINST 10, C01006 (2015).
E. Gaubas, T.Ceponis, V.Kalesinskas, J.Pavlov, J.Vysniauskas, “Simulations of operation dynamics of different type GaN particle sensors”, Sensors 15(3), 5429- 5473 (2015).
E. Gaubas, T.Ceponis, D.Meskauskaite, N.Kazuchits, “Profiling of current transients in capacitor type diamond sensors”, Sensors 15(6), 13424-13458 (2015).