有机金属卤化物钙钛矿的全光可控非线性光学特性及应用

As an emerging optoelectronic material, organic metal halide perovskite has growing interest in the field of solar cells and detectors because of its low cost and high photoelectric conversion efficiency. With the increase of incident light intensity, researchers found that the organic metal halide perovskite presents strong nonlinear optical response and modulation characteristics. Recently, our group also demonstrated the broadband nonlinear optical properties of the organic metal halide perovskite independently. An ultrafast optical pulse has been delivered via the nonlinear optical material introduced into the fiber laser cavity. On the basis of previous work, driven by the demand of broadband, cost-effective nonlinear optical materials and modulators, the project is proposed to study all-optical tunable nonlinear optical properties of perovskite, reveal the physical mechanism of third-order nonlinear optical properties, explore the tunable method and mechanism and develop its application in ultrafast laser. The results will not only help understand the nonlinear optical properties of organic metal halide perovskite, but also expand the potential applications for new conceptual optoelectronics devices.

有机金属卤化物钙钛矿是一种新兴光电材料，其具有高的光电转换效率、低的制备成本等优点，已成为太阳能电池、光电探测器等领域的研究热点。伴随入射光强增加，研究人员发现有机金属卤化物钙钛矿呈现出强的非线性光学响应和调制特性。近期，本课题组也独立实验证明了有机金属卤化物钙钛矿的宽带非线性光学特性，并且基于其饱和吸收特性获得了超快的光纤激光输出。在前期工作基础上，本项目拟针对宽带、低成本非线性光学材料及其调制器件的应用需求，理论结合实验研究有机金属卤化物钙钛矿的全光可控非线性光学特性，揭示其三阶非线性光学特性的物理机制，探索其在宽波段范围内三阶非线性光学特性的调控机制及方法，并发展其在超快激光产生等方面的应用。研究结果不仅有助于加深对有机金属卤化物钙钛矿非线性光学特性的认识，更有助于拓展未来有机金属卤化物钙钛矿光电器件的应用潜力。

金属卤化物钙钛矿因其电子结构可调，光电性能优异等特点获得了广泛的关注。本项目在前期工作的基础上，采用宽波段激光光源对有机金属卤化物钙钛矿等低维材料的三阶非线性光学响应特性进行表征，获得其宽波段的三阶非线性光学参数及影响规律；揭示钙钛矿三阶非线性光学特性的物理机制；探索有机金属卤化物钙钛矿等低维材料在宽波段范围内三阶非线性光学特性的调控机制及方法，并发展其在超快激光产生等方面的应用。具体研究成果如下：首先，我们获得了高质量的准二维金属卤化物钙钛矿溶液和薄膜材料。其次，我们实验研究了准二维钙钛矿等低维材料宽波段的非线性光学响应，通过双带模型进一步验证了金属卤化物钙钛矿在宽波段激光作用下的三阶非线性响应随波长变化的特性。最后，我们探索了有机金属卤化物钙钛矿等低维材料在全光调控，超快激光产生等方面的应用。