Strain-induced band gap tuning in flexible ferroelectric/mica thin films

THIN SOLID FILMS

卷:731

Article

Sun, Yu^1,2  Wong, Ki Hei²  Kwok, Kin Wing² 

[1] Xidian Univ, Acad Adv Interdisciplinary Res, Sch Adv Mat & Nanotechnol, Xian 710126, Peoples R China

[2] Hong Kong Polytech Univ, Dept Appl Phys, Kowloon, Hong Kong, Peoples R China

关键词: Ferroelectric;    Thin film;    Strain;    Band gap;   

DOI  :  10.1016/j.tsf.2021.138741

来源: Elsevier

【 摘 要 】

Precise control of the band gap is crucial for lead-free ferroelectrics in the application of high-performance optical devices. In this work, we demonstrate that continuous and reversible tuning of optical band gap can be realized through mechanical strain in flexible Ba0.9Ca0.1Ti0.975Fe0.025O3 (BCTF)/mica films. Through bending the flexible films, a large mechanical strain of 0.85% could be introduced into the ferroelectric active layer, leading to a reduction in the band gap of 0.38 eV. The strong dependence of the optical band gap on mechanical bending mainly arisen from the strain-induced modification of Fe-O bond. Because of the superior mechanical property of mica, the flexible BCTF/mica film also exhibits excellent anti-fatigue characteristics over 103 bending cycles. Thus, this work provides an alternate perspective for the design and fabrication of ferroelectric optical devices that cover the entire visible light region.

【 授权许可】

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