Wu Xiaojian, Kim Mijin, Qu Haoran, Wang YuHuang
Department of Chemistry and Biochemistry, University of Maryland, 8051 Regent Drive, College Park, MD, 20742, USA.
Maryland NanoCenter, University of Maryland, College Park, MD, 20742, USA.
Nat Commun. 2019 Jun 17;10(1):2672. doi: 10.1038/s41467-019-10788-8.
Chemical defects that fluoresce in the shortwave infrared open exciting opportunities in deep-penetration bioimaging, chemically specific sensing, and quantum technologies. However, the atomic size of defects and the high noise of infrared detectors have posed significant challenges to the studies of these unique emitters. Here we demonstrate high throughput single-defect spectroscopy in the shortwave infrared capable of quantitatively and spectrally resolving chemical defects at the single defect level. By cooling an InGaAs detector array down to -190 °C and implementing a nondestructive readout scheme, we are able to capture low light fluorescent events in the shortwave infrared with a signal-to-noise ratio improved by more than three orders-of-magnitude. As a demonstration, we show it is possible to resolve individual chemical defects in carbon nanotube semiconductors, simultaneously collecting a full spectrum for each defect within the entire field of view at the single defect limit.
在短波红外波段发出荧光的化学缺陷为深度穿透生物成像、化学特异性传感和量子技术带来了令人兴奋的机遇。然而，缺陷的原子尺寸以及红外探测器的高噪声给这些独特发射体的研究带来了重大挑战。在此，我们展示了短波红外波段的高通量单缺陷光谱技术，它能够在单缺陷水平上对化学缺陷进行定量和光谱分辨。通过将铟镓砷探测器阵列冷却至 -190°C 并实施无损读出方案，我们能够在短波红外波段捕获低光荧光事件，信噪比提高了三个多数量级。作为演示，我们表明可以分辨碳纳米管半导体中的单个化学缺陷，在单缺陷极限下同时在整个视场内为每个缺陷收集完整光谱。
