Copper-Zinc-Tin-Sulfur Thin Film Using Spin-Coating Technology

Abstract

Cu 2 ZnSnS 4 (CZTS) thin films were deposited on glass substrates by using spin-coating and an annealing process, which can improve the crystallinity and morphology of the thin films. The grain size, optical gap, and atomic contents of copper (Cu), zinc (Zn), tin (Sn), and sulfur (S) in a CZTS thin film absorber relate to the concentrations of aqueous precursor solutions containing copper chloride (CuCl 2 ), zinc chloride (ZnCl 2 ), tin chloride (SnCl 2 ), and thiourea (SC(NH 2 ) 2 ), whereas the electrical properties of CZTS thin films depend on the annealing temperature and the atomic content ratios of Cu/(Zn + Sn) and Zn/Sn. All of the CZTS films were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDXS), Raman spectroscopy, and Hall measurements. Furthermore, CZTS thin film was deposited on an n-type silicon substrate by using spin-coating to form an Mo/p-CZTS/n-Si/Al heterostructured solar cell. The p-CZTS/n-Si heterostructured solar cell showed a conversion efficiency of 1.13% with V oc = 520 mV, J sc = 3.28 mA/cm 2 , and fill-factor (FF) = 66%.

Synthesis and Characterization of Copper-Zinc-Tin-Sulfide (CZTS) Thin Film Absorber Layer for Solar Cell Application

“…The CZTS thin film shows the (112), (220) and (312) planes corresponding to 2θ values of about 28.437°, 47.302° and 56.094° respectively. This result is almost congruent with the previous studies [17][18][19][20][21]. This ensures that the polycrystalline tetragonal structure, that is CZTS, is formed.…”

“…In 2016 Yeh et al [19] demonstrated the deposition of CZTS thin films by spin coating method. They showed the variation of optical band gap of CZTS with Cu/(Zn+Sn) ratio where the band gap ranges from about 1.7 eV to about 1.4 eV and also obtained the cell conversion efficiency of 1.13%.…”

Importance of CdS buffer layer thickness on Cu2ZnSnS4-based solar cell efficiency

“…For electrically high quality CZTS absorber films, it is necessary to increase the formation of Zn Sn acceptors and to diminish the Sn Zn donors. This might be possible when the Zn/Sn ratio is higher than 1 [31].…”

Simulation study to find suitable dopants of CdS buffer layer for CZTS solar cell

“…Up to 21% and 21.7% efficiency have been achieved for second generation CdTe and CIGS solar cell [6]. But due to the toxicity of cadmium and selenium, and less availability of tellurium and indium, an alternative material CZTS has achieved great attraction among the researchers during last couple of years [7,8].…”