通过Ag阵列耦合增强少层InSe的光学响应  

Efficient enhancement of photoluminescence and second-harmonic generation of few-layer InSe coupled with surface-plasmonic Ag prism array

作　　者：孙荣欢 刘勇 陈荧 蒋琪 陈平安 帅钦 骆子煜 杨鑫 蒋英 胡袁源 陈舒拉 潘安练 Ronghuan Sun;Yong Liu;Ying Chen;Qi Jiang;Pingan Chen;Qin Shuai;Ziyu Luo;Xin Yang;Ying Jiang;Yuanyuan Hu;Shula Chen;Anlian Pan(Department of Key Laboratory for Micro-Nano Physics and Technology of Hunan Province,State Key Laboratory of Chemo/Biosensing and Chemometrics,College of Materials Science and Engineering,Hunan University,Changsha 410082,China;Department of School of Physics and Electronics,Hunan University,Changsha 410082,China)

机构地区：[1]Department of Key Laboratory for Micro-Nano Physics and Technology of Hunan Province,State Key Laboratory of Chemo/Biosensing and Chemometrics,College of Materials Science and Engineering,Hunan University,Changsha 410082,China [2]Department of School of Physics and Electronics,Hunan University,Changsha 410082,China

出　　处：《Science China Materials》2023年第7期2788-2794,共7页中国科学（材料科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(62175061,52172140,52221001,and 52072117);the Natural Science Foundation of Hunan Province(2022JJ30167);the Outstanding Scholarship Program of Hunan Province(2021JJ10021);China Postdoctoral Science Foundation(BX20220104,2022M720046 and 2022TQ0100)。

摘　　要：具有高发光性能的二维材料被认为是实现光电器件应用的极具前途的材料.其中,硒化铟(InSe)是一种具有代表性的二维材料,近些年在光电领域表现出巨大的应用潜力,因此吸引了研究者们的广泛关注.然而,InSe的光-物质相互作用极其微弱,因为其带隙激子的偏振取向是面外的,主要被面外偏振光激发而对正常入射光(面内偏振)的响应极其微弱,这大大限制了其在光电器件中的实际应用.在此,我们提出了一种方法,即通过将少层InSe转移到Ag纳米棱镜阵列上,显著提升InSe在线性和非线性体系的光学响应.结合实验分析,增强的机理主要来自于两种机制的协同作用:一方面,局域表面等离子体共振产生的局部强化电磁场垂直分布于金属表面,与面外偏振的InSe带隙激子发生高效耦合,增强了InSe的光-物质相互作用;另一方面,独特设计的弯曲结构增加了入射光在平面外的偏振分量,促使InSe面外激子对光的吸收和散射效率增强.通过进一步调整InSe的厚度,我们实现了光致发光和二次谐波信号的两个数量级的增强.因此,我们的工作为改善InSe的光学特性提供了一个有效的途径,使其在光电器件的实际应用中迈出了重要的一步.Two-dimensional(2D)materials with exotic photophysical effects and prominent optical performance are considered suitable nanobuilding blocks for optoelectronic device applications.Among these materials,indium selenide(InSe)has attracted enormous research attention owing to its unique structure,high layer-tunable optical response in the visible to near-infrared regions,and substantial second-order nonlinear optical properties.However,InSe features an extremely weak response to normal incident light(in-plane polarization)because its band-edge excitons are oriented out-ofplane,which considerably limits its practical applications.Herein,by integrating few-layer InSe with an Ag nanoprism array,we substantially improved the optical response of InSe in linear and nonlinear regimes.The enhanced response is attributable to the synergy between two mechanisms.First,the resonant excitation of the local surface plasma enhances the coupling efficiency of InSe with the incident light;second,the unique bending structure increases the out-of-plane polarization component of the incident light,resulting in enhanced light absorption and scattering by the out-of-plane excitons at the InSe band edge.We further achieved a two-order magnitude enhancement in the photoluminescence and secondharmonic generation intensities by tuning the InSe thickness.This paper proposes an effective approach for improving the optical properties of InSe,contributing to its practical applications in optoelectronic devices.

关 键 词：INSE Ag prism array localized surface plasmon resonance optical response modulation PHOTOLUMINESCENCE SHG intensity enhanced 

分 类 号：TB34[一般工业技术—材料科学与工程]