The Properties of ITO/Arc-ZnO Passivating Layer for TCO Conducting Substrate Deposited by RF Magnetron Sputtering

Abstract

Abstract. In this work, a thermally stable multilayered transparent conducting oxide (TCO) utilizing ZnO antireflective thin film (arc-ZnO) has been prepared by RF magnetron sputtering. The novel ITO/arc-ZnO conducting substrate with blocking layer capabilities has been designed using step-down interference coating structure based on double layer antireflection coating (DLAR). The XRD result revealed a mixed-oriented type of crystalline structure between ITO and ZnO with preferred [222] and [002] orientations, respectively. The antireflection behaviour of multilayer ITO/arc-ZnO is evidence with the presence of two maximum peaks overshoots at 440 nm and 750 nm range while eliminating approximately 92% reflectance, hence contributes to higher overall transmittance (≥ 87%) in the mid-wavelength region. The ITO/arc-ZnO blocking layers conserves the low resistivity of ITO at 5.71 x 10-4 Ω cm, even after oxidizing during air annealing process above 400 °C. These results demonstrate that the multilayered ITO/arc-ZnO with tailored refractive index substrate is a realistic approach for higher overall transmittance with good stability in electrical properties, prolonged with an added capability of suppressing back electron transfer that is foreseen suitable for dye sensitized solar cell application.