Research Article of International Journal of Nanoparticle Research
Processing and Characterization of Vacuum-Free CuInSe2 Thin Films from Nanoparticle-Precursors using Novel Temperature Treatment Techniques
Matthias Schuster*, Philipp Sisterhenn, Lorenz Graf, Peter J. Wellmann
Materials Department 6 (i-MEET), Martensstr. 7, 91058 Erlangen, Germany, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU)
The objective of this work is the processing and characterization of a dense CuInSe2 solar-cell-absorber-layer based on nanoparticulate precursors. Bimetallic copper-indium- and elemental selenium-nanoparticles were synthesized by wet-chemical processes and then dispersed in organic solvents as nano-inks. These inks were then printed into different layer-stacks on a molybdenum coated float-glass-substrate via doctor-blading. The temperature treatment to transform these layer-stacks into dense CISe thin films was investigated, using a face-to-face technique and mechanically applied pressure or the repetition of coating and annealing. All absorber layers were characterized with SEM, EDX and XRD. Dense, coarse grained CuInSe2 layers with a thickness ≈ 7 µm were formed and the application of mechanical pressure shows potential to reduce thickness and sinter together the nanoparticles to large grains of ca. 3 µm in size. The face-to-face-annealing ensured keeping a stoichiometric ratio of (Cu+In) / Se ≈ 1, and can help reducing the content of oxides, even when the annealing is performed in ambient atmosphere. With a repetition of coating and annealing, dense CISe layers could be produced at low temperature of only 350 °C.
Keywords: CuInSe2, solar cell absorber, nanoparticles, vacuum-free, face-to-face annealing, uniaxial pressure
How to cite this article:
Matthias Schuster*, Philipp Sisterhenn, Lorenz Graf, Peter J. Wellmann. Processing and Characterization of Vacuum-Free CuInSe2 Thin Films From Nanoparticle-Precursors Using Novel Temperature Treatment Techniques. International Journal of Nanoparticle Research, 2018; 2:4.
 P. Jackson, D. Hariskos, R. Wuerz, O. Kiowski, A. Bauer, T.M. Friedlmeier, et al., Properties of Cu(In,Ga)Se 2 solar cells with new record efficiencies up to 21.7%, Phys. Status Solidi – Rapid Res. Lett. 9 (2015) 28–31. doi:10.1002/pssr.201409520.
 I. Repins, M.A. Contreras, B. Egaas, C. Dehart, J. Scharf, C.L. Perkins, 19.9% -efficient ZnO / CdS / CuInGaSe 2 Solar Cell with 81.2 % Fill Factor, Prog. Photovoltaics Res. Appl. 16 (2008) 235–239. doi:10.1002/pip.
 F.O. Adurodija, M.J. Carter, R. Hill, Synthesis and characterization of CuInSe 2 thin films from Cu , In and Se stacked layers using a closed graphite box, Sol. Energy Mater. Sol. Cells. 40 (1996) 359–369.
 S.M.F. Hasan, M.A. Subhan, K.M. Mannan, The optical and electrical properties of copper indium di-selenide thin films, Opt. Mater. (Amst). 14 (2000) 329–336.
 G. Chen, L. Wang, X. Sheng, H. Liu, X. Pi, D. Yang, Chemical synthesis of Cu(In) metal inks to prepare CuInS2 thin films and solar cells, J. Alloys Compd. 507 (2010) 317–321. doi:10.1016/j.jallcom.2010.07.190.
 J. Chang, J.H. Lee, J.H. Cha, D.Y. Jung, G. Choi, G. Kim, Bimetallic nanoparticles of copper and indium by borohydride reduction, Thin Solid Films. 519 (2011) 2176–2180. doi:10.1016/j.tsf.2010.11.038.
 A.R. Ingole, S.R. Thakare, N.T. Khati, A. V. Wankhade, D.K. Burghate, Green synthesis of selenium nanoparticles under ambient condition, Chalcogenide Lett. 7 (2010) 485–489.
 A.L. Stroyuk, A.E. Raevskaya, S.Y. Kuchmiy, V.M. Dzhagan, D.R.T. Zahn, S. Schulze, Structural and optical characterization of colloidal Se nanoparticles prepared via the acidic decomposition of sodium selenosulfate, Colloids Surfaces A Physicochem. Eng. Asp. 320 (2008) 169–174. doi:10.1016/j.colsurfa.2008.01.055.
 W. Zhang, X. Zhang, L. Zhang, J. Wu, Z. Hui, Y. Cheng, et al., A redox reaction to synthesize nanocrystalline Cu2-xSe in aqueous solution., Inorg. Chem. 39 (2000) 1838–9. http://www.ncbi.nlm.nih.gov/pubmed/11428101.
 Y. Min, G.D. Moon, J. Park, M. Park, U. Jeong, Surfactant-free CuInSe₂ nanocrystals transformed from In₂Se₃ nanoparticles and their application for a flexible UV photodetector., Nanotechnology. 22 (2011) 465604. doi:10.1088/0957-4484/22/46/465604.
 S.A. Möckel, T. Wernicke, M. Arzig, P. Köder, M. Brandl, M. Distaso, et al., Low Temperature Formation of CuInSe 2 Solar Cell Absorbers by an All Printed Two Species Nanoparticulate Se + Cu – In Precursor, Thin Solid Films. 582 (2015) 60–68.
 M. Schuster, M. Distaso, S.A. Möckel, U. Künecke, W. Peukert, P.J. Wellmann, Synthesis of In2Se3 and Cu2-xSe Micro- and Nanoparticles with Microwave-Assisted Solvothermal and Aqueous Redox Reactions for the Preparation and Stabilization of Printable Precursors for a CuInSe2 Solar Cell Absorber Layer, Energy Procedia. 84 (2015) 62–70. doi:10.1016/j.egypro.2015.12.296.
 M. Schuster, S.A. Möckel, R.A. Wibowo, R. Hock, P.J. Wellmann, Optimising The Parameters For The Synthesis Of CuIn-Nanoparticles By Chemical Reduction Method For Chalcopyrite Thin Film Precursors, MRS Proc. 1538 (2013) 203–208. doi:10.1557/opl.2013.980.
 D. Wolf, G. Müller, Kinetics of CIS-formation studied in situ by thin film calorimetry, Thin Solid Films. 362 (2000) 155–160.