Structural and electrical characterization of Cu2ZnSnS4 ingot material grown by melting method

In this work, a Cu2ZnSnS4 (CZTS) ingot is grown via a melting method, then cooled; the resulting molten stoichiometric mixture is sealed off in a quartz ampoule under vacuum. The CZTS powder chemical composition analyses are determined using energy dispersive spectroscopy, and revealing the slightly Cu-rich and Zn-poor character of the ingot. Powder X-ray diffraction analysis reveals a crystalline structure with a kesterite phase formation, and a preferred orientation of (112) plane. The lattice constants of the a- and c- axes, calculated based on the XRD analyses, are a = 5.40 angstrom and c = 10.84 angstrom. Based on Hall measurements at room temperature, we find that the crystal exhibits p-type conductivity, with a high concentration of 10(18) cm(-3), a resistivity of 1.7 omega cm, and a mobility of 10.69 cm(2)V(-1)s(-1). Activation energies are estimated based on an Arrhenius plot of conductivity versus 1/T, for a temperature range of 80-350 K, measuring 35 and 160 meV in low- and high-temperature regimes, respectively, which is attributed to complex defects (2Cu(Zn)+Sn-Zn) and antisite defects (Cu-Zn), respectively. The observed scattering mechanisms are attributed to ionized impurities and acoustic phonons at low and high temperatures, respectively. The extracted band-gap is 1.37 eV.

Automated summary

In this study, a Cu2ZnSnS4 (CZTS) crystal was grown using a melting method, showing a slightly Cu-rich and Zn-poor character with a kesterite phase formation and preferred orientation of (112) plane. The crystal exhibited p-type conductivity with specific lattice constants, and activation energies were estimated for different temperature regimes based on conductivity measurements. Scattering mechanisms were attributed to complex defects and antisite defects, with band-gap extraction yielding a value of 1.37 eV.