High Photostrictive Strain Rate in Ferroelectric AlScN Thin Films

High Photostrictive Strain Rate in Ferroelectric AlScN Thin Films

Advanced Materials

10.1002/adma.202519418

https://doi.org/10.1002/adma.202519418

Hui Li, Shashidhara Acharya, Jin Kyu Han, Ming Sheng Zhang, Pooi See Lee, Jingcong Hu, David Boon Kiang Lim, Percis Teena Christopher Subhodayam, Kui Yao

Photostrictive Strain, Ferroelectric AlScN Thin Films

30 December 2025

Li, H., Acharya, S., Han, J. K., Zhang, M. S., Lee, P. S., Hu, J., Lim, D. B. K., Christopher Subhodayam, P. T., & Yao, K. (2025). High Photostrictive Strain Rate in Ferroelectric AlScN Thin Films. Advanced Materials. Portico. https://doi.org/10.1002/adma.202519418

Photostriction refers to non-thermal strain in materials induced by light, such as through opto-electro-mechanical coupling involving the bulk photovoltaic effect (BPVE) and the converse piezoelectric effect in a ferroelectric material. Conventional ferroelectric photostrictive responses are extremely slow, with strain rates below 10−3 s−1 due to the long timescale of BPVE, limiting their use in high-frequency or signal transmission applications. This work demonstrates a significantly enhanced photostrictive strain rate of 3.6 s−1 in scandium aluminium nitride (Al0.58Sc0.42N) thin films under modulated continuous light excitation. The light-induced strain amplitude is equivalent to that of electric-field induced strain with 2 V applied across the film, underscoring the significant and competitive opto-mechanical coupling. This fast response is attributed to nanoscale columnar domains that reduce the electric time delay and charge carrier drift distances, enabling rapid strain generation. The demonstrated fast photostriction provides a unique pathway for light-driven actuation and acoustic wave excitation without requiring electrical wiring, electrodes or electric poling, thus, opening opportunities for developing acoustic micro-actuators and novel optomechanical systems operating in a non-contact mode.

Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

This research / project is supported by the A*STAR - Industry Alignment Fund – Industry Collaboration Projects Grant
Grant Reference no. : I2301E0027

This research / project is supported by the A*STAR - Distinguished Fellowship Award
Grant Reference no. : NA

This research / project is supported by the A*STAR - Graduate Scholarship (AGS)
Grant Reference no. : NA

This is the peer reviewed version of the following article: Li, H., Acharya, S., Han, J. K., Zhang, M. S., Lee, P. S., Hu, J., Lim, D. B. K., Christopher Subhodayam, P. T., & Yao, K. (2025). High Photostrictive Strain Rate in Ferroelectric AlScN Thin Films. Advanced Materials. Portico. https://doi.org/10.1002/adma.202519418 , which has been published in final form at 10.1002/adma.202519418. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.

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