CsPbBr_(3)光波导中激子局域场和复合速率的增强

Localized Field and Recombination Rate Enhancement of Excitons in CsPbBr_(3)Optical Waveguide

将银膜和聚甲基丙烯酸甲酯(PMMA)及高增益的钙钛矿CsPbBr_(3)集成一个平面光波导,通过对体系的物理机理和光学特性研究,探索等离子体结构新应用的可能。实验结果表明,随着体系结构的改变,特别是对PMMA厚度的调制,发现局域在银膜和钙钛矿CsPbBr_(3)界面电磁场增强,使得CsPbBr_(3)激子的发光和辐射速率(Γ=τ-1)增强。我们用双指数衰减和描述系综衰减的延展模型分别进行了讨论,发现二者有较大的差别。采用双指数衰减拟合求寿命没考虑系综的限域效应和银/CsPbBr_(3)界面上传播表面等离极化激元(SPPs)引起的局域场增强,所以在自由空间拟合得到的平均荧光寿命τavg在30~25 ns范围,与先前报道结果接近。而用系综衰减的延展模型得到τavg在12~9 ns范围,荧光寿命显著变小即辐射速率增强。上述研究对开发表面等离激元发光显示器件和光物理基础研究提供了依据。

In this paper,Ag,PMMA and perovskite CsPbBr_(3)films have been integrated into a plane waveguides to explore the optical physical mechanism and new application of plasmon structure.It is shown that the localized field on the Ag/perovskite CsPbBr_(3)interface has been increased giving rise to PL and radiative ratio(Γ=τ-1)enhancement of CsPbBr_(3)excitons as varying system structures,especially modifying the thickness of PMMA.Decay curves have been fitted by both two exponential and ensemble stretched functions,respectively.It is found that there is big fitting discrepancy.Without considering the localized field enhancement on the Ag/CsPbBr_(3)interface,the fit results(τavg,30~25 ns)by two exponential form are similar to the results in free space reported previously.The PL lifetime shortening(τavg,12~9 ns),or radiative rate increasing have been found by the latter fitting.The above-mentioned investigations can provide the basis for optical physical fundamental research and design and developing of surface plasmon polaritons(SPPs)luminescence-display devices.