Mechanically tunable sub-10nm metal gap by stretching PDMS substrate
Mechanically tunable sub-10nm metal gap by stretching PDMS substrate
复制标题
通过拉伸 PDMS 基底实现机械可调亚 10nm 金属间隙
DOI：
10.1088/1361-6528/aa5366
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发表时间：
2017
期刊：
影响因子：
3.5
通讯作者：
Jin Chongjun
中科院分区：
文献类型：
--
作者：
Liu Wenjie;Shen Yang;Xiao Guohui;She Xiaoyi;Wang Jianfang;Jin Chongjun
在亚10 nm或亚纳米金属纳米间隙中操纵光对于研究电磁波与物质之间的强相互作用至关重要。然而，具有精确控制的尺寸和高通量的金属纳米间隙的制造仍然是一个挑战。在这里，我们开发了一种方法，通过机械拉伸过程主动控制相邻金属纳米颗粒之间的差距距离从140 nm到亚10 nm甚至0 nm。为了证明这种方法，我们制造了一个正方形晶格的聚二甲基硅氧烷（PDMS）基板上的金盘阵列，通过干涉光刻和金沉积，和子10 nm的粒子间的间隙，实现了作为施加100%的应变的PDMS基板。透射光谱显示偶极共振峰明显红移，禁带宽度从140 nm变窄到10 nm以下。实验和理论证明了纳米尺度下的差距距离与宏观尺度下的PDMS基底拉伸量之间存在一个普适的标度关系。我们的方法可以连续、可逆地调节差距距离，在表面增强拉曼散射、单光子发射和电荷量子隧穿等方面具有潜在的应用前景。
Manipulating light in sub-10 nm or subnanometer metal nanogaps is crucial to study the strong interaction between electromagnetic waves and matters. However, the fabrication of metallic nanogaps with precisely controlled size and high-throughput still remains a challenge. Here, we developed an approach to actively control the gap distance between adjacent metal nanoparticles from 140 nm to sub-10 nm or even 0 nm via mechanical stretching process. To demonstrate this method, we manufactured the gold disk arrays in a square lattice on the polydimethylsiloxane (PDMS) substrate through interference lithography and gold deposition, and sub-10 nm interparticle gap was achieved as exerting a strain of 100% to the PDMS substrate. Transmission spectra show a remarkable red shift of the dipole resonance with narrowing gap from 140 nm to sub-10 nm. Importantly, a universal scaling law between the gap distance in nanoscale and the stretching amount of PDMS substrate in macroscopic scale were demonstrated experimentally and theoretically. Our method can tune the gap distance continuously and reversibly, suggesting potential applications in surface-enhanced Raman scattering, single photon emitter and quantum tunneling of electric charge.