liu.seSök publikationer i DiVA
Ändra sökning
Länk till posten
Permanent länk

Direktlänk
BETA
Storasta, Liutauras
Publikationer (10 of 36) Visa alla publikationer
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
Öppna denna publikation i ny flik eller fönster >>Nonequilibrium carrier diffusion and recombination in heavily-doped and semi-insulating bulk HTCVD grown 4H-SiC crystals
Visa övriga...
2005 (Engelska)Ingår i: Materials Science Forum, Vols. 483-485, 2005, Vol. 483, s. 409-412Konferensbidrag, Publicerat paper (Refereegranskat)
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.

Nyckelord
four-wave mixing, 4H-SiC, carrier transport
Nationell ämneskategori
Teknik och teknologier
Identifikatorer
urn:nbn:se:liu:diva-48225 (URN)
Konferens
ECSCRM2004
Tillgänglig från: 2009-10-11 Skapad: 2009-10-11 Senast uppdaterad: 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
Öppna denna publikation i ny flik eller fönster >>Observation of recombination enhanced defect annealing in 4H-SiC
2005 (Engelska)Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 86, nr 9, s. 91903-Artikel i tidskrift (Refereegranskat) 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.

Nationell ämneskategori
Naturvetenskap
Identifikatorer
urn:nbn:se:liu:diva-24609 (URN)10.1063/1.1811381 (DOI)6785 (Lokalt ID)6785 (Arkivnummer)6785 (OAI)
Tillgänglig från: 2009-10-07 Skapad: 2009-10-07 Senast uppdaterad: 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
Öppna denna publikation i ny flik eller fönster >>Recombination enhanced defect annealing in 4H-SiC
2005 (Engelska)Ingår i: Materials Science Forum, Vols. 483-485, 2005, Vol. 483, s. 369-372Konferensbidrag, Publicerat paper (Refereegranskat)
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.

Nyckelord
SiC, radiation damage, enhanced annealing
Nationell ämneskategori
Teknik och teknologier
Identifikatorer
urn:nbn:se:liu:diva-48224 (URN)
Konferens
ECSCRM2004
Tillgänglig från: 2009-10-11 Skapad: 2009-10-11 Senast uppdaterad: 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).
Öppna denna publikation i ny flik eller fönster >>Characterization and comparison of 4H-SiC(112 over-bar 0) and 4H-SiC(0001) 8° off-axis substrates and homoepitaxial films
Visa övriga...
2004 (Engelska)Ingår i: Materials Research Society Symposium Proceedings, Vol. 815 Silicon Carbide 2004 - Materials, Processing and Devices,2004, 2004, s. 53-58Konferensbidrag, Publicerat paper (Övrigt vetenskapligt)
Nationell ämneskategori
Naturvetenskap
Identifikatorer
urn:nbn:se:liu:diva-41246 (URN)55395 (Lokalt ID)55395 (Arkivnummer)55395 (OAI)
Konferens
Materials Research Society Symposium
Tillgänglig från: 2009-10-10 Skapad: 2009-10-10 Senast uppdaterad: 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
Öppna denna publikation i ny flik eller fönster >>Deep levels created by low energy electron Irradiation in 4H-SiC
Visa övriga...
2004 (Engelska)Ingår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 96, nr 9, s. 4909-4915Artikel i tidskrift (Refereegranskat) 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.

Nationell ämneskategori
Teknik och teknologier
Identifikatorer
urn:nbn:se:liu:diva-45596 (URN)10.1063/1.1778819 (DOI)
Tillgänglig från: 2009-10-11 Skapad: 2009-10-11 Senast uppdaterad: 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
Öppna denna publikation i ny flik eller fönster >>Electronic structure of deep defects in SiC
Visa övriga...
2004 (Engelska)Ingår i: Silicon Carbide: Recent Major Advances / [ed] W.J. Choyke, H. Matsunami, G. Pens, Berlin, Heidelberg: Springer Verlag , 2004, s. -899Kapitel i bok, del av antologi (Övrigt vetenskapligt)
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.

Ort, förlag, år, upplaga, sidor
Berlin, Heidelberg: Springer Verlag, 2004
Serie
Advanced texts in physics, ISSN 1439-2674
Nationell ämneskategori
Naturvetenskap
Identifikatorer
urn:nbn:se:liu:diva-45173 (URN)79898 (Lokalt ID)978-3-540-40458-3 (ISBN)3-540-40458-9 (ISBN)79898 (Arkivnummer)79898 (OAI)
Tillgänglig från: 2009-10-10 Skapad: 2009-10-10 Senast uppdaterad: 2015-09-22Bibliografiskt granskad
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.
Öppna denna publikation i ny flik eller fönster >>Growth of Homoepitaxial Films on 4H-SiC(11-20)and 8° Off-Axis 4H-SiC(0001) Substrates and their Characterization
Visa övriga...
2004 (Engelska)Ingår i: Materials Science Forum, Vols. 457-460, Mater. Sci. Forum, Vol. 457-460: Trans Tech Publications Inc. , 2004, s. 221-Konferensbidrag, Publicerat paper (Refereegranskat)
Ort, förlag, år, upplaga, sidor
Mater. Sci. Forum, Vol. 457-460: Trans Tech Publications Inc., 2004
Nationell ämneskategori
Naturvetenskap
Identifikatorer
urn:nbn:se:liu:diva-41235 (URN)55382 (Lokalt ID)55382 (Arkivnummer)55382 (OAI)
Konferens
ICSCRM2003
Tillgänglig från: 2009-10-10 Skapad: 2009-10-10 Senast uppdaterad: 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.
Öppna denna publikation i ny flik eller fönster >>Investigations of possible nitrogen participation in the Z1/Z2 defect in 4H-SiC
2004 (Engelska)Ingår i: Mater. Sci. Forum, Vol. 457-460, Trans Tech Publications Inc. , 2004, s. 469-Konferensbidrag, Publicerat paper (Refereegranskat)
Ort, förlag, år, upplaga, sidor
Trans Tech Publications Inc., 2004
Nationell ämneskategori
Naturvetenskap
Identifikatorer
urn:nbn:se:liu:diva-41233 (URN)55378 (Lokalt ID)55378 (Arkivnummer)55378 (OAI)
Konferens
ICSCRM2003
Tillgänglig från: 2009-10-10 Skapad: 2009-10-10 Senast uppdaterad: 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
Öppna denna publikation i ny flik eller fönster >>Optical and electrical characterization of (Ga,Mn)N/InGaN multiquantum well light-emitting diodes
Visa övriga...
2004 (Engelska)Ingår i: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 33, nr 5, s. 467-471Artikel i tidskrift (Refereegranskat) 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.

Nationell ämneskategori
Naturvetenskap
Identifikatorer
urn:nbn:se:liu:diva-45011 (URN)10.1007/s11664-004-0204-9 (DOI)79413 (Lokalt ID)79413 (Arkivnummer)79413 (OAI)
Tillgänglig från: 2009-10-10 Skapad: 2009-10-10 Senast uppdaterad: 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.
Öppna denna publikation i ny flik eller fönster >>Temperature-Dependent Hall Effect Measurements in Low - Compensated p-Type 4H-SiC
Visa övriga...
2004 (Engelska)Ingår i: Mater. Sci. Forum, Vol. 457-460, Trans Tech Publications Inc. , 2004, s. 677-Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

  

Ort, förlag, år, upplaga, sidor
Trans Tech Publications Inc., 2004
Nationell ämneskategori
Naturvetenskap
Identifikatorer
urn:nbn:se:liu:diva-41217 (URN)55357 (Lokalt ID)55357 (Arkivnummer)55357 (OAI)
Konferens
ICSCRM2003
Tillgänglig från: 2009-10-10 Skapad: 2009-10-10 Senast uppdaterad: 2010-12-15
Organisationer

Sök vidare i DiVA

Visa alla publikationer