Pepe Yasemin, Unlu Bekir Asilcan, Akkoyun Serife, Asci Nurcan, Karatay Ahmet, Ates Aytunc, Elmali Ayhan
Department of Engineering Physics, Faculty of Engineering, Ankara University, Ankara 06100, Türkiye.
Department of Metallurgical and Materials Engineering, Faculty of Engineering and Natural Sciences, Ankara Yıldırım Beyazıt University, Ankara 06010, Türkiye.
ACS Omega. 2025 May 28;10(22):23049-23057. doi: 10.1021/acsomega.5c01091. eCollection 2025 Jun 10.
In this work, the optical limiting performance of titanium dioxide (TiO) particle-filled polyvinylpyrrolidone (PVP) composite nanofibers produced by electrospinning was investigated. Effectively filled PVP composite nanofibers with TiO were observed in the backscattering scanning electron microscopy (SEM) images. A reduced band gap energy of the composite nanofibers was determined with an increasing amount of TiO. Increasing localized defect states were obtained with increasing TiO particles in PVP. Furthermore, open-aperture Z-scan experiments at 532 nm were conducted at different intensities to investigate the composite nanofibers' nonlinear absorption (NA) characteristics. The NA signal was obtained for all composite nanofibers, and their main NA mechanism was 2PA. The 2PA coefficient and the NA coefficient values of the pure PVP nanofibers increased with the increase in TiO filler in the PVP nanofibers. This increment indicated the contribution of absorption originating from localized defects inside the NA. Stronger optical limiting performance with a lower onset optical limiting threshold was observed for higher TiO-filled PVP composite nanofibers. TiO composite nanofibers could be an effective optical limiter in the visible wavelength range due to their strong optical limiting ability, low onset optical limiting threshold, and high optical damage threshold.
在这项工作中，研究了通过静电纺丝制备的填充二氧化钛（TiO）颗粒的聚乙烯吡咯烷酮（PVP）复合纳米纤维的光学限幅性能。在背散射扫描电子显微镜（SEM）图像中观察到TiO有效地填充在PVP复合纳米纤维中。随着TiO含量的增加，复合纳米纤维的带隙能量降低。随着PVP中TiO颗粒的增加，局部缺陷态增多。此外，在不同强度下进行了532nm的开孔Z扫描实验，以研究复合纳米纤维的非线性吸收（NA）特性。所有复合纳米纤维均获得了NA信号，其主要NA机制为双光子吸收（2PA）。纯PVP纳米纤维的2PA系数和NA系数值随着PVP纳米纤维中TiO填料的增加而增大。这一增量表明NA内部局部缺陷引起的吸收的贡献。对于TiO填充量较高的PVP复合纳米纤维，观察到具有较低起始光学限幅阈值的更强光学限幅性能。TiO复合纳米纤维由于其强大的光学限幅能力、低起始光学限幅阈值和高光学损伤阈值，在可见波长范围内可能是一种有效的光学限幅器。
