Imaging with Nanometer Resolution Using Optically Active Defects in Silicon Carbide
Imaging with Nanometer Resolution Using Optically Active Defects in Silicon Carbide
复制标题
DOI：
10.1103/physrevapplied.14.034021
复制
发表时间：
2020-09-09
影响因子：
4.6
通讯作者：
Gu, Min
中科院分区：
文献类型：
--
作者：
Castelletto, Stefania;Barbiero, Martina;Gu, Min
纳米结构和块状碳化硅 (SiC) 材料与电子、纳米和微机械系统以及生物传感应用相关。由于其带隙内点缺陷，碳化硅最近已成为纳米光子学和量子应用的替代平台，从可见光到近红外光发射，是光致发光探针的理想选择。在这里，我们使用单分子定位显微镜，利用带隙内激发，研究 3C 和 4H-SiC 多型体中不同尺寸的块体、量子点和纳米颗粒中 SiC 点缺陷的光致发光 (PL) 特性。我们通过使用不同的激发波长来研究 PL 动力学，并利用点缺陷 PL 间歇性来实现超分辨图像，分辨率为 20 nm，发射器之间的最小距离为 40 nm。我们观察到，虽然 561 nm 是获得足够眨眼行为的理想激发波长，但 638 nm 主要是淬灭 PL。我们进一步在体外将 4H-SiC 纳米颗粒与 MCF10A 细胞一起孵育，并通过结合 561 nm 和 638 nm 激发来观察纳米颗粒在细胞中的超分辨图像。这种方法对于碳化硅荧光纳米晶体及其量子点的应用非常有前景，它具有带隙内色心和表面缺陷的组合，可用于量子纳米光子学、磁传感和生物医学成像，为使用近红外发射的细胞环境中的单粒子跟踪与自旋传感相结合铺平了道路。
Nanostructured and bulk silicon carbide (SiC) materials are relevant for electronics, nano- and micromechanical systems, and biosensing applications. SiC has recently emerged as an alternative platform for nanophotonics and quantum applications due to its intra-band-gap point defects, emitting from the visible to the near-infrared, which are ideal for photoluminescent probes. Here, we use a single-molecule localization microscope to study the photoluminescence (PL) properties of SiC point defects in bulk, quantum dots, and nanoparticles of different sizes in the 3C and 4H-SiC polytypes using intra-band-gap excitation. We study the PL dynamics by using different excitation wavelengths, and we use the point-defect PL intermittency to achieve superresolved images, with a resolution of 20 nm and a minimum distance between emitters of 40 nm. We observe that, while 561 nm is an ideal excitation wavelength to obtain a sufficient blinking behavior, 638 nm is mostly quenching the PL. We further incubate 4H-SiC nanoparticles with MCF10A cells in vitro and observe superresolved images of the nanoparticles in cells by combining 561 and 638 nm excitation. This approach is very promising for the application of SiC fluorescent nanocrystals and their quantum dots, hosting a combination of intra-band-gap color centers and surface defects, for quantum nanophotonics, magnetic sensing, and biomedical imaging, paving the way for single-particle tracking combined with spin sensing within a cellular environment using near-infrared emission.