Zentrum fur Sonnenenergie und Wasserstoffforschung Baden Wurttemberg ZSW

Stuttgart Mühlhausen, Germany

Zentrum fur Sonnenenergie und Wasserstoffforschung Baden Wurttemberg ZSW

Stuttgart Mühlhausen, Germany

Time filter

Source Type

Dong H.,Karlsruhe Institute of Technology | Schnabel T.,Zentrum fur Sonnenenergie und Wasserstoffforschung Baden Wurttemberg ZSW | Ahlswede E.,Zentrum fur Sonnenenergie und Wasserstoffforschung Baden Wurttemberg ZSW | Feldmann C.,Karlsruhe Institute of Technology
Solid State Sciences | Year: 2014

Cu2ZnSnS4 kesterite nanoparticles (CZTS) with a particle diameter of 10-20 nm are prepared by a polyol-mediated synthesis with diethylene glycol as the liquid phase. The polyol - a high-boiling multidentate alcohol - allows controlling the particle size and agglomeration as well as preparing readily crystalline nanoparticles. The as-prepared kesterite nanoparticles exhibit an overall composition of Cu1.56Zn 1.29Sn1.16S4.59 and a band gap of 1.37 eV. As a first test, thin-film solar cells are manufactured after layer deposition of the as-prepared CZTS nanoparticles and conversion to Cu2ZnSn(S,Se) 4 (CZTSSe) via gas-phase selenization. The volume increase of about 15% due to the CZTS-to-CZTSSe conversion supports the formation of a dense layer, reduces the interparticulate surfaces and leads to a reduction of the band gap to 1.14 eV. The chemical composition of the as-prepared CZTS nanoparticles and of the deposited CZTSSe thin film prior and after selenization are studied in detail by energy-dispersive X-ray spectroscopy, Raman spectroscopy and X-ray fluorescence analysis. All these methods confirm the intended copper-poor and zinc-/tin-rich CZTS/CZTSSe composition. The resulting thin-film solar cells show an open-circuit voltage of 247.3 mV, a short-circuit current density of 21.3 mA/cm2, a fill factor of 41.1% and a power-conversion efficiency of 2.2%. © 2014 Elsevier Masson SAS. All rights reserved.


Dong H.,Karlsruhe Institute of Technology | Quintilla A.,Zentrum fur Sonnenenergie und Wasserstoffforschung Baden Wurttemberg ZSW | Cemernjak M.,Zentrum fur Sonnenenergie und Wasserstoffforschung Baden Wurttemberg ZSW | Popescu R.,Karlsruhe Institute of Technology | And 3 more authors.
Journal of Colloid and Interface Science | Year: 2014

Selenium nanoparticles with diameters of 100-400nm are prepared via hydrazine-driven reduction of selenious acid. The as-prepared amorphous, red selenium (a-Se) particles were neither a stable phase nor were they colloidally stable. Due to phase transition to crystalline (trigonal), grey selenium (t-Se) at or even below room temperature, the particles merged rapidly and recrystallized as micronsized crystal needles. As a consequence, such Se particles were not suited for layer deposition and as a precursor to manufacture thin-film CIS (copper indium selenide/CuInSe2) solar cells. To overcome this restriction, Se@CuSe core@shell particles are presented here. For these Se@CuSe core@shell nanoparticles, the phase transition a-Se→t-Se is shifted to temperatures higher than 100°C. Moreover, a spherical shape of the particles is retained even after phase transition. Composition and structure of the Se@CuSe core@shell nanostructure are evidenced by electron microscopy (SEM/STEM), DLS, XRD, FT-IR and line-scan EDXS. As a conceptual study, the newly formed Se@CuSe core@shell nanostructures with CuSe acting as a protecting layer to increase the phase-transition temperature and to improve the colloidal stability were used as a selenium precursor for manufacturing of thin-film CIS solar cells and already lead to conversion efficiencies up to 3%. © 2013 Elsevier Inc.

Loading Zentrum fur Sonnenenergie und Wasserstoffforschung Baden Wurttemberg ZSW collaborators
Loading Zentrum fur Sonnenenergie und Wasserstoffforschung Baden Wurttemberg ZSW collaborators