Solution-Processed Pb(Zr,Ti)O₃Thin Films with Strong Remnant Pockels Coefficient

In contrast to the widely studied electrical properties of Pb(Zr,Ti)O 3 thin films, which have led to their applicability in various application areas such as thin film capacitors, microelectronics, and ferroelectric memories, the electro-optic (EO) properties are far less studied, which hinders the applicability of Pb(Zr,Ti)O 3 films for EO applications such as heterogeneously integrated phase modulators in silicon (Si) photonics. Therefore, the EO properties of Pb(Zr,Ti)O 3 films need to be further investigated to pave the way for the applicability of Pb(Zr,Ti)O 3 films in EO applications. As the EO properties of ferroelectric thin films strongly depend on their crystal phase and texture, which in turn are influenced by the method of film fabrication. Therefore, in this work, we investigate the EO properties of a promising solution process using a La 2 O 2 CO 3 template film. We successively characterize the precursor ink, microstructure and EO properties of the solution-processed Pb(Zr,Ti)O 3 film. The Pb(Zr,Ti)O 3 film exhibits a fiber texture and has a large maximum and remnant Pockels coefficient ( r eff ) of 69 pm V –1 and 66 pm V –1, respectively. The integration into a ring resonator-based modulator shows a V π L of 2.019 V cm. The determination of these promising EO properties could further pave the way for the applicability of Pb(Zr,Ti)O 3 thin films in Si photonics.