DEVELOPMENT OF SCREEN PRINTING INK WITH METAL OXIDES NANOPARTICLES

Metal oxides semiconductors such CuO and In₂O₃ have enhanced electronic and optical properties which allows them to be used on electronic devices such as photovoltaic cells (PVs). Thin film PVs such as copper indium gallium diselenide (CIGSe) are usually produced by vacuum co-evaporation and sputtering techniques which are expensive and difficult to scale-up. Therefore, in this work we aim to produce inks for screen printing technology as it is a versatile, low-cost and widely used technique to printed electronics. The ink we develop in this work is formulated with 50 wt% CuO and In₂O₃ nanoparticles with oleic acid, di(propylene glycol) methyl ether (DPM) and poly(vinylpyrrolidone) as solvent, additive and polymer, respectively. After screen printed they were calcined at 500ºC during 30 min. The formulation was optimized in order to ensure a good dispersion of the nanoparticles which allowed to obtain a stable ink. In this work was observed that the functionalization of In₂O₃ with dopamine increased the dispersion of the nanoparticles in the solution.

It is also important to ensure a lower carbon content on semiconductor films as well as a non-porous film to avoid electron-hole recombination. After thermogravimetric analysis (TGA) we verify that the films produced had nearly zero carbon content. To characterize the morphology of our films we used scanning electron microscope (SEM) where we observed a crack free film (Fig.1). The resultant CuO-In₂O₃ screen-printed films were subjected to the selenization, and their structural and microstructural characteristics will be discussed.

Fig.1: SEM picture of CuO-In₂O₃ screen printed film after calcination.

Acknowledgements

This research integrates PrintPV project (P2020-PTDC/CTM-ENE/5387/2014) funded by Fundação para a Ciência e a Tecnologia (FCT/COMPETE2020). We thank our colleagues Prof. Shlomo Magdassi and Yitzchak Rosen from Institute of Chemistry at The Hebrew University of Jerusalem.