Development of Zn1−xSnxO and Mg1−xSnxO transparent conducting oxide thin films for perovskite solar cell applications

Abstract

Abstract Zinc-doped tin oxide (ZTO) and magnesium-doped tin oxide (MTO) transparent conducting oxide (TCO) thin films were synthesized using the atomizer spray pyrolysis method and annealed at 450 °C for application as front electrodes in perovskite solar cells (PSCs). The precursor molar ratio was varied from 0.1:0.1 to 0.1:0.5 (Zn/Mg:Sn), resulting in film thicknesses ranging from 210 to 513 nm for ZTO and 243 to 688 nm for MTO after annealing. X-ray diffraction analysis confirmed improved crystallinity with increased crystallite size after annealing. Optical studies revealed high transmittance of ~ 76–80% in the visible region. The optical bandgap decreased after annealing, from 3.85 to 3.67 eV for ZTO and from 3.82 to 3.40 eV for MTO. Hall effect measurements confirmed n-type conductivity with enhanced electrical performance at higher molar concentrations. The optimized MTO film exhibited a maximum carrier concentration of 2.78 × 10 20  cm −3 , mobility of 31.56 cm 2 /V s, and low resistivity of 1.89 × 10 −4  Ω cm. Photovoltaic devices fabricated using annealed ZTO and MTO substrates achieved power conversion efficiencies of 3.45% and 6.38%, respectively. The improved device performance of MTO-based PSCs is attributed to its higher conductivity and optical transparency, demonstrating its potential as an alternative cost-effective TCO material for solar cell applications.