A colloidal quantum dot spectrometer
A colloidal quantum dot spectrometer
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DOI：
10.1038/nature14576
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发表时间：
2015-07-02
期刊：
影响因子：
64.8
通讯作者：
Bawendi, Moungi G.
中科院分区：
文献类型：
--
作者：
Bao, Jie;Bawendi, Moungi G.
光谱学几乎应用于每一个科学领域，只要光与物质相互作用(1)。虽然具有令人印象深刻的性能特征的精密仪器是可用的，但在小型化、廉价和易于使用的系统的开发上仍投入了大量的努力（1-13）。目前的微光谱仪设计主要使用干涉滤光片（2-5）和干涉光学(3)，这限制了它们的光子效率、分辨率和光谱范围（2,3）。在这里，我们表明，许多这些限制可以克服由胶体量子点组成的二维吸收滤光片阵列取代干涉光学（14-17）。胶体量子点光谱仪采用波长复用原理（18）测量光谱，而不是通过光栅或基于干涉的窄带滤光片引入时间或空间分离后单独测量光谱的不同波段。多个光谱带分别用一个滤波器和一个检测器（9-12）同时编码和检测，阵列格式允许使用不同编码的不同滤波器多次高效重复该过程，从而获得足够的信息以实现目标光谱的计算重建。我们通过测量光谱峰位置小至1纳米的位移，说明了这种量子点微光谱仪的性能，该光谱仪由195种不同类型的量子点组成，具有覆盖300纳米光谱范围的吸收特征。鉴于这种性能，进一步改进的可证明途径，量子点可以轻松处理和集成，以及它们覆盖广泛光谱范围的许多精细可调带隙，我们预计量子点微光谱仪将在最小尺寸，重量，成本和光谱仪复杂性至关重要的应用中发挥作用。
Spectroscopy is carried out in almost every field of science, whenever light interacts with matter(1). Although sophisticated instruments with impressive performance characteristics are available, much effort continues to be invested in the development of miniaturized, cheap and easy-to-use systems(1-13). Current microspectrometer designs mostly use interference filters(2-5) and interferometric optics(3) that limit their photon efficiency, resolution and spectral range(2,3). Here we show that many of these limitations can be overcome by replacing interferometric optics with a two-dimensional absorptive filter array composed of colloidal quantum dots(14-17). Instead of measuring different bands of a spectrum individually after introducing temporal or spatial separations with gratings or interference-based narrow-band filters, a colloidal quantum dot spectrometer measures a light spectrum based on the wavelength multiplexing principle(18): multiple spectral bands are encoded and detected simultaneously with one filter and one detector(9-12), respectively, with the array format allowing the process to be efficiently repeated many times using different filters with different encoding so that sufficient information is obtained to enable computational reconstruction of the target spectrum. We illustrate the performance of such a quantum dot microspectrometer, made from 195 different types of quantum dots with absorption features that cover a spectral range of 300 nanometres, by measuring shifts in spectral peak positions as small as one nanometre. Given this performance, demonstrable avenues for further improvement, the ease with which quantum dots can be processed and integrated, and their numerous finely tuneable bandgaps that cover a broad spectral range, we expect that quantum dot micro-spectrometers will be useful in applications where minimizing size, weight, cost and complexity of the spectrometer are critical.