Solution-Processed Pb(Zr,Ti)O3 Thin Films with Strong Remnant Pockels Coefficient

Ewout Picavet; Kobe De Geest; Enes Lievens; Hannes Rijckaert; Tom Vandekerckhove; Eduardo Solano; Davy Deduytsche; Laura Van Bossele; Dries Van Thourhout; Klaartje De Buysser; Jeroen Beeckman

doi:10.1021/acsami.4c07073

Solution-Processed Pb(Zr,Ti)O₃ Thin Films with Strong Remnant Pockels Coefficient

ACS Appl Mater Interfaces. 2024 Aug 7;16(31):41134-41144. doi: 10.1021/acsami.4c07073. Epub 2024 Jul 30.

Authors

Ewout Picavet^{1

2}, Kobe De Geest^{2

3}, Enes Lievens^{2

3}, Hannes Rijckaert^{1

2}, Tom Vandekerckhove², Eduardo Solano⁴, Davy Deduytsche⁵, Laura Van Bossele^{1

2}, Dries Van Thourhout³, Klaartje De Buysser¹, Jeroen Beeckman²

Affiliations

¹ SCRiPTS, Department of Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Ghent, Belgium.
² LCP Group, Department of Electronics and Information Systems, Ghent University, Technologiepark - Zwijnaarde 126, 9052 Gent, Belgium.
³ PRG, Department of Information Technology, Ghent University-IMEC, Technologiepark - Zwijnaarde 126, 9052 Gent, Belgium.
⁴ NCD-SWEET beamline, ALBA Synchrotron Light Source, Carrer de la Llum 2-26, 08290 Cerdanyola del Valles̀, Spain.
⁵ CoCooN Group, Department of Solid State Sciences, Ghent University, Krijgslaan 281-S1, 9000 Ghent, Belgium.

PMID: 39077874
DOI: 10.1021/acsami.4c07073

Abstract

In contrast to the widely studied electrical properties of Pb(Zr,Ti)O₃ 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)O₃ films for EO applications such as heterogeneously integrated phase modulators in silicon (Si) photonics. Therefore, the EO properties of Pb(Zr,Ti)O₃ films need to be further investigated to pave the way for the applicability of Pb(Zr,Ti)O₃ 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 La₂O₂CO₃ template film. We successively characterize the precursor ink, microstructure and EO properties of the solution-processed Pb(Zr,Ti)O₃film. The Pb(Zr,Ti)O₃ 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_πL of 2.019 V cm. The determination of these promising EO properties could further pave the way for the applicability of Pb(Zr,Ti)O₃ thin films in Si photonics.

Keywords: Fiber texture; La2O2CO3 template film; Nanophotonic Pockels modulator; Pb(Zr,Ti)O3 film; SiN.