Epitaxial\nZinc Stannate (Zn₂SnO₄) Thin Film for Solar\nCells

Abstract

Epitaxial Zn₂SnO₄ thin films were fabricated\nusing rf magnetron sputtering and characterized via X-ray diffraction\n(XRD) to investigate its structural behaviors. XRD measurements indicate\nhigh-quality single crystal films of (400) orientation. The growth\nfollows cubic-to-cubic alignment with the epitaxial relationship of\nZn₂SnO₄[001]//MgO­[001] in the out-of-plane direction\nand Zn₂SnO₄[110]//MgO­[110] in the in-plane direction.\nThe Hall mobility of 88.5 ± 6.2 cm² V^–1 s^–1 was achieved. The Zn₂SnO₄ films had average optical transmittance ≥90% and a band gap\nof 3.582 ± 0.082 eV. In the optical pump–THz probe spectroscopy\nresult, a relatively longer charge-carrier lifetime, <i>τ</i>_l = 2158.89 ps, was achieved.