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The heterogeneous integration of ferroelectric BaTiO3 thin films on silicon (Si) and silicon nitride (SiN)‐based platforms for photonic integrated circuits (PICs) plays a crucial role in the development of future nanophotonic thin film modulators. Since the electro‐optic (EO) properties of ferroelectric thin films strongly depend on their crystal phase and texture, the integration of BaTiO3 thin films on these platforms is far from trivial. So far, a conventional integration route using a SrTiO3 template film in combination with high vacuum deposition methods has been developed, but it has a low throughput, is expensive and requires monocrystalline substrates. To close this gap, a cost‐efficient, high‐throughput and scalable method for integrating highly textured BaTiO3 films is needed. Therefore, an alternative method for the integration of highly textured BaTiO3 films using a La2O2CO3 template film in combination with a chemical solution deposition (CSD) process is presented. In this work, the structural and EO properties of the solution‐processed BaTiO3 film are characterized and its integration into an optical ring resonator is evaluated. The BaTiO3 film exhibits a fiber texture, has a large Pockels coefficient (reff) of 139 pm V−1, and integration into a ring resonator‐based modulator shows a VπL of 1.881 V cm and a bandwidth of > 40 GHz. This enables low‐cost, high‐throughput, and flexible integration of BaTiO3 films on PIC platforms and the potential large‐scale fabrication of nanophotonic BaTiO3 thin‐film modulators. [ABSTRACT FROM AUTHOR]

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.