Near-field thermal imaging of optically excited gold nanostructures: scaling principles for collective heating with heat dissipation into the surrounding medium†,Nanoscale

当前位置： X-MOL 学术 › Nanoscale › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Near-field thermal imaging of optically excited gold nanostructures: scaling principles for collective heating with heat dissipation into the surrounding medium†
Nanoscale ( IF 5.8 ) Pub Date : 2017-12-19 00:00:00 , DOI: 10.1039/c7nr08349a
Susil Baral _{1,

2,

3,

4} , Ali Rafiei Miandashti _{1,

2,

3,

4} , Hugh H. Richardson _{1,

2,

3,

4}

Affiliation

In this paper, we introduce a new optical temperature and thermal imaging technique combining near-field microscopy and Er³⁺ photoluminescence thermometry. The tip aperture of 120 nm limits the spatial resolution of near-field thermal imaging. We use the technique with two different approaches towards local temperature measurement and thermal imaging. In the first approach, gold nanostructures on top of Al_0.94Ga_0.06N thin film embedded with Er³⁺ ions are optically excited through the SNOM tip with 532 nm CW laser to generate thermal images that have a Gaussian thermal profile because heating and probing are done through a single tip aperture. In the second approach, nanostructures on top of thermal sensor film of AlGaN : Er³⁺ ions deposited on a transparent sapphire substrate are excited with 532 nm CW laser through the substrate with a large spot size (FWHM ∼10 μm) and Er³⁺ emission from the film is collected in transmission mode through the SNOM tip. We use this approach to measure steady-state thermal profiles from optically excited different sized clusters made from 40 nm gold nanoparticles. This approach yields steady-state thermal profiles that have inverse distance temperature decay away from the cluster and we find that the maximum temperature change and temperature decay length into the surrounding medium (r_½) scales with cluster radius.

中文翻译：

光学激发金纳米结构的近场热成像：集中加热并散发到周围介质中的缩放原理†

在本文中，我们介绍了一种结合近场显微镜和Er ³⁺光致发光测温技术的新的光学温度和热成像技术。120 nm的尖端孔径限制了近场热成像的空间分辨率。我们将该技术与两种不同的方法一起用于局部温度测量和热成像。在第一种方法中，用532 nm CW激光通过SNOM尖端对嵌入有Er ³⁺离子的Al _0.94 Ga _0.06 N薄膜顶部的金纳米结构进行光学激发，以生成具有高斯热剖面的热图像，因为加热和探测是通过一个尖端孔完成。在第二种方法中，在AlGaN：Er的热传感器膜顶部形成纳米结构沉积在透明蓝宝石衬底上的³⁺离子被532 nm CW激光激发通过具有大光点大小（FWHM〜10μm）的衬底，并且通过SNOM尖端以透射模式收集薄膜的Er³⁺发射。我们使用这种方法来测量由40 nm金纳米粒子制成的光学激发的不同尺寸簇的稳态热分布。这种方法产生具有反距离温度衰减从集群远稳态热分布，我们发现最大的温度变化和温度衰减长度到周围介质（ ř _½）秤具有群集半径。

更新日期：2017-12-19

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11