Yuan Ye, Cao Fenglin, Li Peng, Wu Jiawen, Zhu Baohua, Gu Yuzong
Physics Research Center for Two-Dimensional Optoelectronic Materials and Devices, School of Physics and Electronics, Henan University, Kaifeng 475004, China.
Nanophotonics. 2022 May 27;11(13):3177-3188. doi: 10.1515/nanoph-2022-0251. eCollection 2022 Jun.
Halide perovskite quantum dots (PQDs) have exhibited significantly superior nonlinear optical properties compared to traditional semiconductor materials thanks to their peculiar physical and electronic structures. By further improving the nonlinear optical properties of PQDs, it is expected to adapt to ultrafast photonics applications. This work reported the nonlinear optical properties of methylammonium lead bromide-graphene (CHNHPbBr-G) composites synthesized by growing CHNHPbBr quantum dots directly from a graphene oxide lattice. Our experiments indicate that the combined advantages of the ultrafast charge transport properties from graphene and the strong charge generation efficiency of perovskite can be integrated together. The CHNHPbBr-G composite exhibited enhanced saturable absorption properties with large modulation depth and very low saturation intensity. The transient absorption spectra and carrier dynamics analysis revealed that the enhancement of the saturated absorption properties of the composites mainly arose from the ultrafast charge transfer between G and CHNHPbBr which promoted the coupling between different states. The results pave the way for the design of optical switches or mode lockers based on saturable absorbers with good performance.
卤化物钙钛矿量子点（PQDs）由于其独特的物理和电子结构，与传统半导体材料相比，展现出显著优越的非线性光学特性。通过进一步改善PQDs的非线性光学特性，有望适应超快光子学应用。这项工作报道了通过直接从氧化石墨烯晶格生长CHNHPbBr量子点合成的甲基溴化铅-石墨烯（CHNHPbBr-G）复合材料的非线性光学特性。我们的实验表明，石墨烯超快电荷传输特性和钙钛矿强电荷产生效率的综合优势可以整合在一起。CHNHPbBr-G复合材料表现出增强的可饱和吸收特性，具有大的调制深度和非常低的饱和强度。瞬态吸收光谱和载流子动力学分析表明，复合材料可饱和吸收特性的增强主要源于G和CHNHPbBr之间的超快电荷转移，这促进了不同状态之间的耦合。这些结果为基于具有良好性能的可饱和吸收体设计光开关或锁模器铺平了道路。
