liu.seSearch for publications in DiVA
Change search
Link to record
Permanent link

Direct link
BETA
Storasta, Liutauras
Publications (10 of 36) Show all publications
Storasta, L., Aleksiejunas, R., Sudzius, M., Kadys, A., Malinauskas, T., Jarasiunas, K., . . . Janzén, E. (2005). Nonequilibrium carrier diffusion and recombination in heavily-doped and semi-insulating bulk HTCVD grown 4H-SiC crystals. In: Materials Science Forum, Vols. 483-485. Paper presented at ECSCRM2004 (pp. 409-412). , 483
Open this publication in new window or tab >>Nonequilibrium carrier diffusion and recombination in heavily-doped and semi-insulating bulk HTCVD grown 4H-SiC crystals
Show others...
2005 (English)In: Materials Science Forum, Vols. 483-485, 2005, Vol. 483, p. 409-412Conference paper, Published paper (Refereed)
Abstract [en]

We applied four-wave mixing (FWM) technique for investigation of high temperature chemical vapour deposition (HTCVD) grown 4H-SiC samples with different doping levels. The determined minority electron and hole mobilities in heavily doped crystals at doping densities of 1019 cm(-3) were found to be equal to 116 and 52 cm(2)/Vs. In semi-insulating (SI) crystals, the ambipolar diffusion coefficient Da = 2.6 - 3.3 cm(2) A and carrier lifetimes of 1.5 - 2.5 ns have been measured. Irradiation of SI crystals by 6 MeV electrons resulted in essential decrease of carrier lifetime down to &SIM, 100 ps and clearly revealed the defect-assisted carrier generation with respect to two-photon interband transitions before irradiation.

Keywords
four-wave mixing, 4H-SiC, carrier transport
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-48225 (URN)
Conference
ECSCRM2004
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2010-12-13
Storasta, L., Carlsson, F. H., Bergman, P. & Janzén, E. (2005). Observation of recombination enhanced defect annealing in 4H-SiC. Applied Physics Letters, 86(9), 91903
Open this publication in new window or tab >>Observation of recombination enhanced defect annealing in 4H-SiC
2005 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 86, no 9, p. 91903-Article in journal (Refereed) Published
Abstract [en]

We report observation of recombination enhanced defect annealing in 4H-SiC detected by capacitance transient spectroscopy and low temperature photoluminescence (PL). Intrinsic defect centers, created by 160 keV electron irradiation, reduce in concentration after illumination at temperatures much lower than previously reported annealing temperatures of 400 and 800 °C. The effect is observed after both external intense above band gap laser excitation, and with recombination in a forward biased pin diode. PL measurements show that several lines, normally detected after electron irradiation, have almost or entirely disappeared by recombination enhanced annealing at room temperature. From capacitance transient measurements, the annealing enhancement is found to be largest for the HS2 hole trap, while the EH1 and EH3 electron traps also anneal out by recombination enhanced reaction but at a lower rate. © 2005 American Institute of Physics.

National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-24609 (URN)10.1063/1.1811381 (DOI)6785 (Local ID)6785 (Archive number)6785 (OAI)
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2017-12-13
Storasta, L., Carlsson, F., Bergman, P. & Janzén, E. (2005). Recombination enhanced defect annealing in 4H-SiC. In: Materials Science Forum, Vols. 483-485. Paper presented at ECSCRM2004 (pp. 369-372). , 483
Open this publication in new window or tab >>Recombination enhanced defect annealing in 4H-SiC
2005 (English)In: Materials Science Forum, Vols. 483-485, 2005, Vol. 483, p. 369-372Conference paper, Published paper (Refereed)
Abstract [en]

Recombination enhanced defect annealing of intrinsic defects in 4H-SiC, created by low energy electron irradiation, has been observed. A reduction the defect concentration at temperature lower than the normal annealing temperature of 400&DEG, C and 800&DEG, C is observed after either above bandgap laser excitation or forward biasing of a pin-diode. The presence of the defects has been studied both electrically and optically using capacitance transient spectroscopy and low temperature photoluminescence. Photoluminescence measurements show that several lines, normally detected after electron irradiation, have almost or entirely disappeared by recombination enhanced annealing at room temperature. From capacitance transient measurements, the annealing enhancement is found to be largest for the HS2 hole trap, while the EH1 and EH3 electron traps also anneal out by recombination enhanced reaction but at a lower rate.

Keywords
SiC, radiation damage, enhanced annealing
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-48224 (URN)
Conference
ECSCRM2004
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2010-12-13
Bishop, S., Preble, E., Hallin, C., Henry, A., Sarney, W., Chang, H.-R., . . . Davis, R. (2004). Characterization and comparison of 4H-SiC(112 over-bar 0) and 4H-SiC(0001) 8° off-axis substrates and homoepitaxial films. In: Materials Research Society Symposium Proceedings, Vol. 815 Silicon Carbide 2004 - Materials, Processing and Devices,2004. Paper presented at Materials Research Society Symposium (pp. 53-58).
Open this publication in new window or tab >>Characterization and comparison of 4H-SiC(112 over-bar 0) and 4H-SiC(0001) 8° off-axis substrates and homoepitaxial films
Show others...
2004 (English)In: Materials Research Society Symposium Proceedings, Vol. 815 Silicon Carbide 2004 - Materials, Processing and Devices,2004, 2004, p. 53-58Conference paper, Published paper (Other academic)
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-41246 (URN)55395 (Local ID)55395 (Archive number)55395 (OAI)
Conference
Materials Research Society Symposium
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2014-10-08
Storasta, L., Bergman, J., Janzén, E., Henry, A. & Lu, J. (2004). Deep levels created by low energy electron Irradiation in 4H-SiC. Journal of Applied Physics, 96(9), 4909-4915
Open this publication in new window or tab >>Deep levels created by low energy electron Irradiation in 4H-SiC
Show others...
2004 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 96, no 9, p. 4909-4915Article in journal (Refereed) Published
Abstract [en]

With low energy electron irradiation in the 80-250 keV range, we were able to create only those intrinsic defects related to the initial displacements of carbon atoms in the silicon carbide lattice. Radiation induced majority and minority carrier traps were analyzed using capacitance transient techniques. Four electron traps (EH1, Z1/Z2, EH3, and EH7) and one hole trap (HS2) were detected in the measured temperature range. Their concentrations show linear increase with the irradiation dose, indicating that no divacancies or di-interstitials are generated. None of the observed defects was found to be an intrinsic defect-impurity complex. The energy dependence of the defect introduction rates and annealing behavior are presented and possible microscopic models for the defects are discussed. No further defects were detected for electron energies above the previously assigned threshold for the displacement of the silicon atom at 250 keV. © 2004 American Institute of Physics. 10.1063/1.1778819.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-45596 (URN)10.1063/1.1778819 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-13
Nguyen, S. T., Wagner, M., Hemmingsson, C., Storasta, L., Magnusson, B., Chen, W., . . . Janzén, E. (2004). Electronic structure of deep defects in SiC. In: W.J. Choyke, H. Matsunami, G. Pens (Ed.), Silicon Carbide: Recent Major Advances: . Berlin, Heidelberg: Springer Verlag
Open this publication in new window or tab >>Electronic structure of deep defects in SiC
Show others...
2004 (English)In: Silicon Carbide: Recent Major Advances / [ed] W.J. Choyke, H. Matsunami, G. Pens, Berlin, Heidelberg: Springer Verlag , 2004, p. -899Chapter in book (Other academic)
Abstract [en]

Since the 1997 publication of Silicon Carbide - A Review of Fundamental Questions and Applications to Current Device Technology edited by Choyke, et al., there has been impressive progress in both the fundamental and developmental aspects of the SiC field. So there is a growing need to update the scientific community on the important events in research and development since then. The editors have again gathered an outstanding team of the world's leading SiC researchers and design engineers to write on the most recent developments in SiC. The book is divided into five main categories: theory, crystal growth, characterization, processing and devices. Every attempt has been made to make the articles as up-to-date as possible and assure the highest standards of accuracy. As was the case for earlier SiC books, many of the articles will be relevant a decade from now so that this book will take its place next to the earlier work as a permanent and essential reference volume.

Place, publisher, year, edition, pages
Berlin, Heidelberg: Springer Verlag, 2004
Series
Advanced texts in physics, ISSN 1439-2674
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-45173 (URN)79898 (Local ID)978-3-540-40458-3 (ISBN)3-540-40458-9 (ISBN)79898 (Archive number)79898 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2015-09-22Bibliographically approved
Bishop, S., Preble, E., Hallin, C., Henry, A., Storasta, L., Jacobson, H., . . . Davis, R. (2004). Growth of Homoepitaxial Films on 4H-SiC(11-20)and 8° Off-Axis 4H-SiC(0001) Substrates and their Characterization. In: Materials Science Forum, Vols. 457-460. Paper presented at ICSCRM2003 (pp. 221). Mater. Sci. Forum, Vol. 457-460: Trans Tech Publications Inc.
Open this publication in new window or tab >>Growth of Homoepitaxial Films on 4H-SiC(11-20)and 8° Off-Axis 4H-SiC(0001) Substrates and their Characterization
Show others...
2004 (English)In: Materials Science Forum, Vols. 457-460, Mater. Sci. Forum, Vol. 457-460: Trans Tech Publications Inc. , 2004, p. 221-Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Mater. Sci. Forum, Vol. 457-460: Trans Tech Publications Inc., 2004
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-41235 (URN)55382 (Local ID)55382 (Archive number)55382 (OAI)
Conference
ICSCRM2003
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2014-10-08
Storasta, L., Henry, A., Bergman, P. & Janzén, E. (2004). Investigations of possible nitrogen participation in the Z1/Z2 defect in 4H-SiC. In: Mater. Sci. Forum, Vol. 457-460. Paper presented at ICSCRM2003 (pp. 469). Trans Tech Publications Inc.
Open this publication in new window or tab >>Investigations of possible nitrogen participation in the Z1/Z2 defect in 4H-SiC
2004 (English)In: Mater. Sci. Forum, Vol. 457-460, Trans Tech Publications Inc. , 2004, p. 469-Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Trans Tech Publications Inc., 2004
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-41233 (URN)55378 (Local ID)55378 (Archive number)55378 (OAI)
Conference
ICSCRM2003
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2014-10-08
Buyanova, I., Izadifard, M., Storasta, L., Chen, W., Kim, J., Ren, F., . . . Zavada, J. M. (2004). Optical and electrical characterization of (Ga,Mn)N/InGaN multiquantum well light-emitting diodes. Journal of Electronic Materials, 33(5), 467-471
Open this publication in new window or tab >>Optical and electrical characterization of (Ga,Mn)N/InGaN multiquantum well light-emitting diodes
Show others...
2004 (English)In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 33, no 5, p. 467-471Article in journal (Refereed) Published
Abstract [en]

 (Ga,Mn)/N/InGaN multiquantum well (MQW) diodes were grown by molecular beam epitaxy (MBE). The current-voltage characteristics of the diodes show the presence of a parasitic junction between the (Ga,Mn)N and the n-GaN in the top contact layer due to the low conductivity of the former layer. Both the (Ga,Mn)N/InGaN diodes and control samples without Mn doping show no or very low (up to 10% at the lowest temperatures) optical (spin) polarization at zero field or 5 T, respectively. The observed polarization is shown to correspond to the intrinsic optical polarization of the InGaN MQW, due to population distribution between spin sublevels at low temperature, as separately studied by resonant optical excitation with a photon energy lower than the bandgap of both the GaN and (Ga,Mn)N. This indicates efficient losses in the studied structures of any spin polarization generated by optical spin orientation or electrical spin injection. The observed vanishing spin injection efficiency of the spin light-emitting diode (LED) is tentatively attributed to spin losses during the energy relaxation process to the ground state of the excitons giving rise to the light emission.

National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-45011 (URN)10.1007/s11664-004-0204-9 (DOI)79413 (Local ID)79413 (Archive number)79413 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2017-12-13
Kassamakova-Kolaklieva, L., Storasta, L., Ivanov, I. G., Magnusson, B., Contreras, S., Consejo, C., . . . Janzén, E. (2004). Temperature-Dependent Hall Effect Measurements in Low - Compensated p-Type 4H-SiC. In: Mater. Sci. Forum, Vol. 457-460. Paper presented at ICSCRM2003 (pp. 677). Trans Tech Publications Inc.
Open this publication in new window or tab >>Temperature-Dependent Hall Effect Measurements in Low - Compensated p-Type 4H-SiC
Show others...
2004 (English)In: Mater. Sci. Forum, Vol. 457-460, Trans Tech Publications Inc. , 2004, p. 677-Conference paper, Published paper (Refereed)
Abstract [en]

  

Place, publisher, year, edition, pages
Trans Tech Publications Inc., 2004
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-41217 (URN)55357 (Local ID)55357 (Archive number)55357 (OAI)
Conference
ICSCRM2003
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2010-12-15
Organisations

Search in DiVA

Show all publications