Achieving composition-controlled Cu₂ZnSnS₄ films by sulfur-free annealing process

Abstract

Cu2ZnSnS4 (CZTS) films were firstly prepared by the nonvacuum spin-coating method, and then annealed at 550 °C in N2 atmosphere. A graphite box was used to inhibit the volatilization of gaseous SnS and S2 to suppress the CZTS decomposition and generation of MoS2 during annealing. The sulfur supplementation carried out in a conventional annealing process was not applied in this work. It was found that Sn loss was overcome and the compositions of postannealed films were close to that of precursor solution. Thus, by this method, the compositions of CZTS films can be controlled by adjusting the elemental ratios of the precursor solution. Besides, the increase in inert atmosphere pressure could further minimize the Sn loss and improve the crystallinity of CZTS films. Furthermore, the resistive MoS2 layer between the CZTS film and the Mo layer was suppressed because sulfur was not used and CZTS decomposition was suppressed.

Role of triethanolamine in forming Cu 2 ZnSnS 4 nanoparticles during solvothermal processing for solar cell applications

“…Figure 1 illustrates the XRD patterns of CZTS thin film fabricated using various TEA concentrations (2, 3, 4, and 5 mg/mL). As presented in Figure 1, diffraction peaks were detected at 2 θ =28.53° (112), 32.98° (200), 47.33° (220), 56.17° (312), and 76.44° (332), suggesting the formation of kesterite‐type CZTS (CZTS, PDF#26‐0575) 23–26 . The diffraction peaks at 2 θ =40.13° (110) were related to the Mo back contact 27 .…”

“…As presented in Figure 1, diffraction peaks were detected at 2θ =28.53 (112), 32.98 (200), 47.33 (220), 56.17 (312), and 76.44 (332), suggesting the formation of kesterite-type CZTS (CZTS, PDF#26-0575). [23][24][25][26] The diffraction peaks at 2θ =40.13 (110) were related to the Mo back contact. 27 For two samples prepared using TEA concentrations (2, and 3 mg/mL), the diffraction peaks located at 2θ =27.05 (100) planes, of the wurtzite CZTS) [28][29][30] The intensity of the peak corresponding to the CZTS phase increased as the TEA concentration increased.…”