Growth and Characterization of Stoichiometric Cu₂ZnSnS₄ Crystal Using Vertical Bridgman Technique

Stoichiometric Cu₂ZnSnS₄ (CZTS) single phase crystals are successfully grown in a single-zone vertical furnace by Bridgman technique. X-ray diffraction (XRD) and Raman spectroscopy measurements are employed to investigate the structural properties of the grown crystals, which verifies the formation of mono-phase CZTS crystals with kesterite structure. The energy-dispersive X-ray analysis (EDS) indicates the growth of CZTS single phase crystals with a nearly stoichiometric chemical composition. The carrier concentration, mobility, and resistivity of the crystals are determined from Hall Effect measurements. At room temperature, the respective values are found to be 4.0 × 10¹⁵ cm⁻³, 1.0 cm² Vs⁻¹, and 1540 Ω cm. The activation energies for the acceptor levels are also determined using the temperature-dependent hole concentration measurement. Cu_Zn-antisite originated acceptor level with activation energies of ≈121 meV is identified in a nearly stoichiometric kesterite structure.