摘要
The plasmon-enhanced second-harmonic generation(SHG)of Au nanorods(NRs),Au-Ag NRs,and asymmetric Au@CdSe heterorods are comparatively investigated.The Au@CdSe tip-and side-heterorods are synthesized by precisely controlling the concentration of Cd2+precursor,and the plasmon resonances can be well tuned simultaneously.The SHG of asymmetric Au@CdSe heterorods has been greatly enhanced with up to 617.7-fold enhancement compared with the Au NRs because of the asymmetric morphology and local field enhancement.Moreover,the harmonic energy transfer induced by the local interband transition of Au has also been demonstrated by the excitation-wavelengthdependent SHG in the Au NRs and Au@CdSe side-heterorods,while it is negligible in the Au-Ag NRs and Au@CdSe tipheterorods because of the presence of Ag.The plasmon-enhanced SHG of asymmetric Au@CdSe heterorods enables potential applications ranging from sensing to biological spectroscopy.
本工作对比研究了金纳米棒、金-银纳米棒及非对称Au@CdSe异质纳米棒中等离激元增强的二次谐波性质.通过精确控制镉离子的浓度,制备了顶端生长和侧边生长的非对称Au@CdSe异质纳米棒,并实现了等离激元共振波长的调控.由于非对称的结构和局域场增强效应,相比于金纳米棒,非对称Au@CdSe异质纳米棒的二次谐波增强倍数最大可达617.7.此外,二次谐波激发谱表明在金纳米棒和侧边生长的Au@CdSe异质纳米棒中存在着由金的带间跃迁引起的谐波能量转移.而由于银的存在,谐波能量转移在金-银纳米棒和顶端生长的Au@CdSe异质纳米棒中可以忽略.非对称Au@CdSe异质纳米棒中等离激元增强的二次谐波在传感、生物光谱等领域都具有潜在应用.
作者
Biao Wu
Peng-Fei Wang
Yun-Hang Qiu
Shan Liang
Zhi-Yong Wu
Li Zhou
Qu-Quan Wang
吴彪;王鹏飞;邱运航;梁珊;武志勇;周利;王取泉(Key Laboratory of Artificial Micro-and Nano-structures of the Ministry of Education,Department of Physics,Wuhan University,Wuhan 430072,China;Jiangxi Key Laboratory of Nanomaterials and Sensors,Provincial Key Laboratory of Optoelectronic and Telecommunication,College of Physics and Communication and Electronics,Jiangxi Normal University,Nanchang 330022,China;Department of Physics,Hunan Normal University,Changsha 410081,China;The Institute for Advanced Studies,Wuhan University,Wuhan 430072,China)
基金
supported by the National Key R&D Program of China(2017YFA0303402)
the National Natural Science Foundation of China(11874293,91750113,11674254 and 11504105)。
