Growth of Cu₂ZnSnS₄ Thin Films by Sulfurization of Co-Sputtered Metallic Precursors

Abstract

CZTS thin films are fabricated by sulfurizing co-sputtered metallic precursor CuZnSn layers under H2S atmosphere. The precursor layers are Cu-poor, Zn-rich deposited and the fabricated films are about 2 µm in thickness. A closed-tube process is preferred with regard to its producing large closely pack grains with smooth surface. XRD and Raman confirm the CZTS structure and the impurities on the surface are removed after suitable chemistry treatments. The band gap of the CZTS is determined to be 1.48 eV by extrapolation. Some more CZTS films are product with slightly changed parameters, sulfurization time, temperature and concentration of H2S, respectively. It is supposed that beside sulfurization time, the temperature could be more significant than concentration of H2S in the closed system.

Growth of Cu2ZnSnS4 absorber layer on flexible metallic substrates for thin film solar cell applications

“…14). Straight line intercepting the photon energy axis gives the optical band gap energy, E g , as 1.57 eV, which is in good agreement with the previously reported values [64]. The transmittance spectrum is given as an inset plot of Fig.…”

Development of a Selective Chemical Etch To Improve the Conversion Efficiency of Zn-Rich Cu2ZnSnS4 Solar Cells

“…This chemical approach supports the high selectivity of our proposed etching process for the ZnS binary phase. It is important to note that the solubility of Sn-rich phases in HCl is noted by Timmo, Mellikov, and Li in CZTS, ,, but the presence of SnS in Zn-rich films tends to be related to peculiarities of that specific system, i.e., a Sn-rich surface or localized SnS phase formation due to Sn layer nonuniformity. In fact, by using inductively coupled plasma mass spectroscopy (ICP-OES), we estimate that the solubility of ZnS is ∼2 orders of magnitude greater under similar dissolution conditions than that of SnS (see SI for more details).…”

Fabrication of Cu<inf>2</inf>ZnSnS<inf>4</inf> thin film by sulfurization of stacked solution-based precursors with different copper sources

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