Nanoelectronics LaNaSC - Laboratory for Nanostructured Solar Cells

The Laboratory for Nanostructured Solar Cells (LaNaSC) develops nano- and micro-structures of chalcopyrite-type semiconductors (Cu(In,Ga)Se2) for application in photovoltaic energy conversion.

We currently follow four research lines:

Development of growth methods for chalcopyrite nanostructures, i.e. quantum dots and nanowires. The goal is to combine the excellent light absorbing properties of chalcopyrite-type materials with the quantum properties of nanostructured materials, and thereby provide a pathway for the enhancement of power conversion efficiencies of photovoltaic devices beyond the Shockley-Queisser limit.

Development of micro solar cells for micro-concentrator solar cell applications. The goal is to develop highly efficient solar cells with a significant reduction in usage of absorber materials.

Development of nanostructures for chalcopyrite thin-film solar cells. The goal is to use passivation and light management techniques to improve solar cell performance.

Development and application of scanning probe microscopy techniques for the characterization of solar cell materials and light-induced phenomena at the nanometer scale.

The laboratory is equipped with a materials preparation facility consisting in a molecular beam epitaxy (MBE) setup for the growth of chalcopyrite-type semiconductors.

The lab also operates an ultra-high vacuum scanning probe microscope, combining STM, AFM, and KPFM facilities with surface photovoltage methods to study light-induced phenomena at the nanometer scale. 

Kamal Abderrafi, Vanessa Iglesias, Nicoleta Nicoara, Pedro Salomé, Sascha Sadewasser 

We are always open for new team members. If you are interested in joining us and applying for external funding (i.e. Marie Curie, FCT, etc.), please contact Sascha by email.



"Incorporation of alkali metals in chalcogenide solar cells"
P.M.P. Salomé, H. Rodriguez-Alvarez, S. Sadewasser
Solar Energy Materials & Solar Cells, 143, 9 (2015)
"Influence of varying Cu content on growth and performance of Ga-graded Cu(In,Ga)Se2 solar Cells"
Piotr Szaniawski, Pedro Salomé, Viktor Fjällström, Tobias Törndaht, Uwe Zimmermann, Marika Edoff
IEEE J. PV 5, 1775 (2015)
"Recovery after potential induced degradation of Cu(In,Ga)Se2 solar cells with CdS and Zn(O,S) buffer layers"
V. Fjällström, P. Szaniawski, B. Vermang, P.M.P. Salomé, F. Rostvall, U. Zimmermann and M.Edoff
IEEE J. Photovoltaics 5, 664 (2015).
“Anomalous persistent photoconductivity in Cu2ZnSnS4 thin films and solar cells”
A. Abelenda, M. Sánchez, G.M. Ribeiro, P.A. Fernandes, P.M.P. Salomé, A.F. da Cunha, J.P. Leitão, M.I.N. da Silva, J.C. González
Solar Energy Materials & Solar Cells 137, 164 (2015).
“Reliable wet-chemical cleaning of natively oxidized high-efficiency Cu(In,Ga)Se2 thin-film solar cell absorbers”
J. Lehmann, S. Lehmann, I. Lauermann, Th. Rissom, Ch.A. Kaufmann, M.Ch. Lux-Steiner, M. Bär, and S. Sadewasser
J. Appl. Phys. 116, 233502 (2014).
“Electroluminescence of copper-nitride nanocrystals”
A. Strózecka, J. Li, R. Schürmann, G. Schulze, M. Corso, F. Schulz, Ch. Lotze, S. Sadewasser, K.J. Franke, and J.I. Pascual
Phys. Rev. B 90,195420 (2014).
“Introduction of Si PERC rear contacting design to boost efficiency of Cu(In,Ga)Se2 solar cells”
B. Vermang, J.T. Wätjen, Ch. Frisk, V. Fjällström, F. Rostvall, M. Edoff, P. Salomé, J. Borme, N. Nicoara, S. Sadewasser
IEEE J. Photovoltaics 4, 1644 (2014).
“Secondary crystalline phases identification in Cu2ZnSnSe4 thin films: contributions from Raman scattering and photoluminescence”
P. M. P. Salomé, P. A. Fernandes, J. P. Leitão, M.G. Sousa, J. P. Teixeira, and A. F. Cunha
Journal of Material Science 49, 7425 (2014).
“Optimizing Ga-profiles for highly efficient Cu(In,Ga)Se2 thin film solar cells in simple and complex defect models”
Ch. Frisk, Ch. Platzer Björkman, J. Olsson, P. Szaniawski, T. Wätjen, V. Fjällström, P. Salomé, M. Edoff
J. Phys. D: Appl. Phys. 47, 485104 (2014).
“Comparison of fluctuating potentials and DAP transitions in a Cu-poor Cu2ZnSnS4 based solar cell”
J.P. Teixeira, R.A. Sousa, M.G. Sousa, A.F. da Cunha, P.A. Fernandes, P.M.P. Salomé, J.C. González, and J.P. Leitão
Appl. Phys. Lett. 105, 163901 (2014).
“Radiative transitions in highly doped and compensated chalcopyrites and kesterites: The case of Cu2ZnSnS4”
J. P. Teixeira, R. A. Sousa, M. G. Sousa, A. F. da Cunha, P. A. Fernandes, P. M. P. Salomé and J. P. Leitão
Phys. Rev. B 90, 235202 (2014).
“Muonium states in Cu2ZnSnS4 solar cell material”
H.V. Alberto, R.C. Vil, J.M. Gil, J. Piroto Duarte, R.B.L. Vieira, A. Weidinger J.P. Leitão, A.F. da Cunha, M.G. Sousa, J.P. Teixeira, P. A. Fernandes, P.M.P. Salomé, K. Timmo, M. Loorits, A. Amato, H.Luetkens, T. Prokscha, A. Suter and Z. Salman
J. Phys.: Conference Series 551, 012045 (2014).
“A 1D Fickian diffusional model for the formation of the double Ga-gradient in three-stage Cu(In,Ga)Se2
H. Rodriguez-Alvarez, S. Sadewasser
J. Appl. Phys. 115, 204913 (2014)
“Properties of electronic potential barriers at grain boundaries in Cu(In,Ga)Se2 thin films”
R. Baier, C. Leendertz, D. Abou-Ras, M.Ch. Lux-Steiner, and S. Sadewasser
Sol. Energy Mat. Sol. Cells 130, 124 (2014).
“Comparative study of Cu(In,Ga)Se2 / CdS and Cu(In,Ga)Se2 / In2S3 systems by surface photovoltage techniques”
Th. Dittrich, A. Gonzáles, T. Rada, T. Rissom , E. Zillner, S. Sadewasser, M.Ch. Lux-Steiner
Thin Solid Films 535, 357 (2013).
“Formation of CuInSe2 and Cu(In,Ga)Se2 thin-films by three thermal co-evaporation: a real-time X-ray diffraction and fluorescence study”
H. Rodriguez-Alvarez, A. Weber, J. Lauche, C. A. Kaufmann, T. Rissom, D. Greiner, M. Klaus, T. Unold, C. Genzel, H.-W. Schock, R. Mainz 
Adv. Energy Mater. (2013).
"Real-time study of Ga diffusion processes during the formation of Cu(In,Ga)Se2: the role of Cu and Na content”
H. Rodriguez-Alvarez, R. Mainz, R. Caballero, D. Abou-Ras, M. Klaus, S. Gledhill, A. Weber, C. A. Kaufmann, H.-W. Schock
Sol. Energy Mat. Sol. Cells 116, 102 (2013).
"Recrystallization of Cu(In,Ga)Se2 thin films studied by X-ray diffraction"
H. Rodriguez-Alvarez, N. Barreau, C.A. Kaufmann, A. Weber, M. Klaus, T. Painchaud, H.-W. Schock, R. Mainz
Acta Materialia 61, 4347 (2013).
“Zinc diffusion in polycrystalline Cu(In,Ga)Se2 and single-crystal CuInSe2 layers”
J. Bastek, N.A. Stolwijk, R. Wuerz, A. Eicke, J. Albert, and S. Sadewasser
Appl. Phys. Lett. 101, 074105 (2012).
“Electrostatic potentials at Cu(In,Ga)Se2 grain boundaries - experiment and simulations”
S.S. Schmidt, D. Abou-Ras, S. Sadewasser, W. Yin, C. Feng, Y. Yan
Phys. Rev. Lett. 109, 095506 (2012).
“Scanning probe microscopy of solar cells: From inorganic thin films to organic photovoltaics”
J.R. O’Dea, L.M. Brown, N. Hoepker, J.A. Marohn, and S. Sadewasser
Materials Research Society Bulletin 37, 642 (2012).
“Electronic properties of grain boundaries in Cu(In,Ga)Se2 thin films with various Ga-contents“
R. Baier, J. Lehmann, S. Lehmann, Th. Rissom, Ch.A. Kaufmann, A. Schwarzmann, Y. Rosenwaks, M.Ch. Lux-Steiner, and S. Sadewasser
Sol. Energy Mat. Sol. Cells 103, 86 (2012).
“Towards quantitative Kelvin probe force microscopy of nanoscale potential distributions”
R. Baier, C. Leendertz, M.Ch. Lux-Steiner, and S. Sadewasser
Phys. Rev. B 85, 165436 (2012).
“Junction formation of Cu3BiS3 investigated by Kelvin probe force microscopy and surface photovoltage measurements”
F. Mesa, W. Chamorro, W. Vallejo, R. Baier, Th. Dittrich, A. Grimm, M.Ch. Lux-Steiner, and S. Sadewasser
Beilstein J. Nanotechnol. 3, 277-284 (2012).
“Chalcopyrite Semiconductors for Quantum Well Solar Cells”
M. Afshar, S. Sadewasser, J. Albert, S. Lehmann, D. Abou-Ras, D. Fuertes Marrón, A.A. Rockett, E. Räsänen, and M.Ch. Lux-Steiner
Adv. Energy Materials 1, 1109 (2011).


Former Group Members

  • Henrique Limborço, Visiting Scientist, 02/2014-02/2015, now at Universidade Federeal de Minas Gerais, Brazil
  • David Fuertes Marrón. Visiting Scientist, 06-09/2013, now at Universidad Polytécnica de Madrid, Spain.
  • Humberto Rodriguez-Alvarez. Research fellow, 03/2012-03-2014, now at Helmholz-Zentrum Berlin, Germany


Group manager Sascha Sadewasser