*Theodoros Dimopoulos¹, Martin Bauch¹, Selina Götz¹, Rachmat Adhi Wibowo¹, Neha Bansal¹, Markus Valtliner², Giovanni Ligorio³, Emil List-Kratochvil³, Christian Linke⁴, Enrico Franzke⁴, Joerg Winkler^4
1Austrian Institute of Technology, Vienna, Austria; ²Vienna University of Technology, Vienna, Austria; ³Humboldt-Universität zu Berlin, Berlin, Germany; ⁴Plansee SE, Reutte, Austria
Indium-tin-oxide (ITO) is the most implemented transparent electrode for thin film photovoltaics and optoelectronics. Currently there is intensive research to replace ITO with a lower-cost alternative, without compromising the transparent electrode’s performance. To this end, dielectric/metal/dielectric (DMD) electrodes offer decreased material costs and better mechanical stability for flexible device applications, while featuring high transparency and low sheet resistance. In this work we present DMD electrodes on glass and PET, based on mixed MoO_x-TiO_x (MTO) dielectrics and Ag or Au as metals. Through proper engineering of the sputter target, direct current (DC) magnetron deposition could be used to sputter the oxides at high rates. MTO films of high transparency could be obtained. Optical simulations have defined the optimal electrode architecture that maximizes the average transmittance in the visible range. Experimental transmittance values >70% (including the substrate) were achieved in all cases, with sheet resistance below 10 Ω/sq. on glass and PET substrate. The energy band structure of the electrodes, measured by UPS, shows suitability for hole extraction in devices, such as perovskite solar cells. To this end, we have investigated the electrodes’ stability upon processing with standard materials used in perovskite solar cell fabrication and the photovoltaic performance of these devices.