BST(Ba0.5Sr0.5TiO3)/PZT(Pb0.52Zr0.48TiO3) photonic crystals were fabricated by magnetron sputtering and annealed at 620°C−700°C. By controlling the crystallinity and the oxygen vacancies of the ferroelectric photonic crystals, the optically and electrically controllable terahertz wave modulations were realized. The variation in refractive index of the 680°C annealed sample showed the highest modulation to the optical pump and increased to 11.9 due to the highest absorption near 532 nm. In the optical pump, the electrons from Ti3+ 2p3/2 ions could be stimulated and captured by Ti4+ 2p3/2 ions, and the ratio of Ti3+/Ti4+ observed increased with the increasing annealing temperature, indicating the increasing oxygen vacancies concentration, which increased the 532 nm optical absorption and contributed to the improved optical modulation. The excess Pb migrating to the surface at higher annealing temperature might be one reason for the degradation of optical modulation. The increasing polarization and leakage current could contribute to the increasing permittivity and loss with the increasing annealing temperature. Two different results were observed on the sample annealed at 680°C when the order of applying external optical and electric fields was changed, due to the different migration mechanisms of excited carriers. This work provides a potentially effective approach to fabricate THz sensing, imaging, and communications devices with multi-function in the modulation of optical and electric multi-fields.

中文翻译：

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热处理 BST/PZT 铁电光子晶体的太赫兹波调制特性

BST(Ba0.5Sr0.5TiO3)/PZT(Pb0.52Zr0.48TiO3)光子晶体通过磁控溅射制备并在620°C-700°C下退火。通过控制铁电光子晶体的结晶度和氧空位，实现了光学和电学可控的太赫兹波调制。680°C 退火样品的折射率变化显示出对光泵的最高调制，并由于在 532 nm 附近的最高吸收而增加到 11.9。在光泵中，Ti3+ 2p3/2 离子可以激发并捕获 Ti4+ 2p3/2 离子，观察到的 Ti3+/Ti4+ 比值随着退火温度的升高而增加，表明氧空位浓度增加，从而增加了532 nm 光吸收并有助于改进光调制。在较高的退火温度下迁移到表面的过量 Pb 可能是光调制退化的原因之一。随着退火温度的升高，极化和漏电流的增加可能导致介电常数和损耗的增加。由于受激载流子的迁移机制不同，当改变施加外部光和电场的顺序时，在 680°C 下退火的样品上观察到两种不同的结果。这项工作为制造在光和电多场调制中具有多功能的太赫兹传感、成像和通信设备提供了一种潜在有效的方法。随着退火温度的升高，极化和漏电流的增加可能导致介电常数和损耗的增加。由于受激载流子的迁移机制不同，当改变施加外部光和电场的顺序时，在 680°C 下退火的样品上观察到两种不同的结果。这项工作为制造在光和电多场调制中具有多功能的太赫兹传感、成像和通信设备提供了一种潜在有效的方法。随着退火温度的升高，极化和漏电流的增加可能导致介电常数和损耗的增加。由于受激载流子的迁移机制不同，当改变施加外部光和电场的顺序时，在 680°C 下退火的样品上观察到两种不同的结果。这项工作为制造在光和电多场调制中具有多功能的太赫兹传感、成像和通信设备提供了一种潜在有效的方法。