Dr. rer. nat. Tim Niewelt

Researcher, Division Solar Cells - Development and Characterization

Research focus

  • Charge carrier lifetime measurement based on photoluminescence effects
  • experimental and physical limitations
     
  • Investigation of limitations of monocrystalline silicon due to crystal defects
  • light-induced degradation
  • oxygen-related defects in Czochralski silicon
  • metal impurities

Curriculum vitae

since 2017 Postdoctoral Researcher at Fraunhofer ISE and the University of Freiburg
2012-2017
PhD thesis "Lifetime-limiting defects in monocrystalline silicon" at University of Freiburg and Fraunhofer ISE
2012 Diploma in Materials Science (Engineering) from Technical University Darmstadt (with distinction)
2010 Intern at Schott Solar (Alzenau)
2008-2009 
Student research assistant at Fraunhofer LBF
2006-2012 
Student at Technical University Darmstadt (materials science)

Publications

External publication list on Google Scholar

Publication list from the Fraunhofer-Publica database:

YearTitle/AuthorDocument Type
2019Imaging Interstitial Iron Concentrations in Gallium-Doped Silicon Wafers
Post, R.; Niewelt, T.; Schön, J.; Schindler, F.; Schubert, M.C.
Journal Article
2019Lifetime-limiting defects in monocrystalline Silicon
Niewelt, Tim; Weber, Eike R. (Referent); Glunz, Stefan W. (Referent)
Dissertation
2018Carrier-Selective Contacts for High-Efficiency Silicon Solar Cells: Presentation held at Photovoltaic Conference, PVCon 2018, Ankara, Turkey, 4-6 July 2018
Glunz, S.; Feldmann, F.; Polzin, J.; Steinhauser, B.; Müller, R.; Fell, A.; Richter, A.; Niewelt, T.; Schindler, F.; Kökbudak, G.; Turan, R.; Nogay, G.; Löper, P.; Young, D.L.; Lee, B.G.; Stradins, P.; Bivour, M.; Cariou, R.; Benick, J.; Dimroth, F.; Hermle, M.
Presentation
2018Limiting Effects in Crystalline Silicon for High-Efficiency Solar Cells: Presentation held at 28th Annual NREL Silicon Workshop 2018, Winter Park, Colorado, USA, 12 - 15 August 2018
Niewelt, T.; Richter, A.; Eberle, R.; Post, R.; Schön, J.; Schindler, F.; Hermle, M.; Kwapil, W.; Schubert, M.
Presentation
2018An open source based repository for defects in silicon
Juhl, Mattias K.; Heinz, Friedemann D.; Coletti, Gianluca; Macdonald, Daniel; Rougieux, Fiacre E.; Schindler, Florian; Niewelt, Tim; Schubert, Martin C.
Conference Paper
2018Taking monocrystalline silicon to the ultimate lifetime limit
Niewelt, Tim; Richter, Armin; Kho, T.C.; Grant, N.E.; Bonilla, R.S.; Steinhauser, Bernd; Polzin, Jana-Isabelle; Feldmann, Frank; Hermle, Martin; Murphy, J.D.; Phang, S.P.; Kwapil, Wolfram; Schubert, Martin C.
Journal Article
2018Taking Monocrystalline Silicon to the Ultimate Lifetime Limit: Presentation held at 8th International Conference on Crystalline Silicon Photovoltaics 2018, Lausanne, Switzerland, 19-21 March 2018
Niewelt, T.; Richter, A.; Kho, T.; Grant, N.; Bonilla, R.; Steinhauser, B.; Polzin, J.-I.; Feldmann, F.; Hermle, M.; Murphy, J.; Phang, S.; Kwapil, W.; Schubert, M.C.
Presentation
2017Experimental evidence of electron capture and emission from trap levels in Cz silicon
Heinz, F.D.; Niewelt, T.; Schubert, M.C.
Journal Article
2017Kinetics of carrier-induced degradation at elevated temperature in multicrystalline silicon solar cells
Kwapil, W.; Niewelt, T.; Schubert, M.C.
Journal Article
2017Light-induced activation and deactivation of bulk defects in boron-doped float-zone silicon
Niewelt, T.; Selinger, M.; Grant, N.; Kwapil, W.M.; Murphy, J.D.; Schubert, M.C.
Journal Article
2017Long-term stability of aluminum oxide based surface passivation schemes under illumination at elevated temperatures
Niewelt, T.; Kwapil, W.M.; Selinger, M.; Richter, A.; Schubert, M.C.
Journal Article
2017Stability of effective lifetime of float-zone silicon wafers with AlOx surface passivation schemes under illumination at elevated temperature
Niewelt, T.; Kwapil, W.; Selinger, M.; Richter, A.; Schubert, M.C.
Journal Article
2017Superacid-treated silicon surfaces: Extending the limit of carrier lifetime for photovoltaic applications
Grant, N.E.; Niewelt, T.; Wilson, N.R.; Wheeler-Jones, E.C.; Bullock, J.; Al-Amin, M.; Schubert, M.C.; Veen, A.C. van; Javey, A.; Murphy, J.D.
Journal Article
2017Understanding the light-induced degradation at elevated temperatures: Similarities between multicrystalline and floatzone p-type silicon
Niewelt, T.; Schindler, F.; Kwapil, W.; Eberle, R.; Schön, J.; Schubert, M.C.
Conference Paper
2016Experimental proof of the slow light-induced degradation component in compensated n-type silicon
Niewelt, T.; Schön, J.; Broisch, J.; Rein, S.; Haunschild, J.; Warta, W.; Schubert, M.C.
Conference Paper
2016Fast in-situ photoluminescence analysis for a recombination parameterization of the fast BO defect component in silicon
Niewelt, T.; Mägdefessel, S.; Schubert, M.C.
Journal Article
2016Identification of lifetime limiting defects by temperature- and injection-dependent photoluminescence imaging
Schön, J.; Youssef, A.; Park, S.; Mundt, L.E.; Niewelt, T.; Mack, S.; Nakajima, K.; Morishita, K.; Murai, R.; Jensen, M.A.; Buonassisi, T.; Schubert, M.C.
Journal Article
2016Swirl Defect Investigation Using Temperature- and Injection-Dependent Photoluminescence Imaging
Youssef, A.; Schön, J.; Niewelt, T.; Mack, S.; Park, S.; Nakajima, K.; Morishita, K.; Murai, R.; Jensen, M.A.; Buonassisi, T.; Schubert, M.C.
Conference Paper
2016A unified parameterization of the formation of boron oxygen defects and their electrical activity
Niewelt, T.; Schön, J.; Broisch, J.; Mägdefessel, S.; Warta, W.; Schubert, M.C.
Journal Article
2015Characterization and modelling of the boron-oxygen defect activation in compensated n-type silicon
Schön, J.; Niewelt, T.; Broisch, J.; Warta, W.; Schubert, M.C.
Journal Article
2015Electrical characterization of the slow boron oxygen defect component in Czochralski silicon
Niewelt, T.; Schön, J.; Broisch, J.; Warta, W.; Schubert, M.C.
Journal Article
2015Spatially resolved impurity identification via temperature- and injection-dependent photoluminescence imaging
Mundt, L.; Schubert, M.C.; Schön, J.; Michl, B.; Niewelt, T.; Schindler, F.; Warta, W.
Journal Article
2014Interstitial oxygen imaging from thermal donor growth - a fast photoluminescence based method
Niewelt, T.; Lim, S.; Holtkamp, J.; Schön, J.; Warta, W.; Macdonald D.; Schubert, M.C.
Journal Article
2012Broad Range Injection-Dependent Minority Carrier Lifetime from Photoluminescence
Giesecke, J.; Niewelt, T.; Rüdiger, M.; Rauer, M.; Schubert, M.; Warta, W.
Journal Article
2012Passivation layers for indoor solar cells at low irradiation intensities
Rühle, K.; Rauer, M.; Rüdiger, M.; Giesecke, J.; Niewelt, T.; Schmiga, C.; Glunz, S.W.; Kasemann, M.
Journal Article
This publication list has been generated from the publication database Fraunhofer-Publica.