Low Emissivity Property of Amorphous Oxide Multilayer (SIZO/Ag/SIZO) Structure

Interest in to the energy saving technology of by adopting low emissive glass for conventional building has been rapidly increasing [1]. Low emissivity (Low-e) glass has been widely used to increase the energy efficiency of windows. Low-e glass has advantages, such as a high transmittance of about 80% or more in the visible range and a low emissivity in the infrared (IR) range [2]. Recently, OMO (oxide/metal/oxide) multilayer structures have emerged as an alternative to low emissive coatings because they provide good optical and electrical characteristics [1-3]. They are fabricated on glass substrates with a middle layer of Ag as a thin metal layer sandwiched between two outer oxides layers [3]. TCO (transparent conduction oxide) thin films have been extensively studied for use as electrodes in optoelectronic devices such as solar cells, organic light emitting diodes, and flat-panel display devices [4-6]. The essential conditions of TCO materials are high conductivity and transparency at a visible range (380 nm < λ < 780 nm). Sn-doped indium oxide (ITO) thin films have been practically commercialized due to their low resistivity and high transparency in the visible range. However, Zn oxide based TCO has emerged as an alternative material to ITO, due to its low cost, wide bandgap, low absorption in the visible region, and good stability under an ambient atmosphere [7-9]. Amorphous silicon indium zinc oxide (SIZO) semiconductor has was high transparencyt and a smooth surface [10]. In this paper, we have investigated Low-e coatings with an OMO structure using amorphous SIZO/Ag/SIZO multilayers. Amorphous SIZO transparent semiconducting layers were fabricated and were then observed. The observation showed the possibility of improved optical property and the reduction of the use of Ag, showing the potential application of low emissivity coating with low cost.