Sugathan Anumol, Bhattacharyya Biswajit, Kishore V V R, Kumar Abhinav, Rajasekar Guru Pratheep, Sarma D D, Pandey Anshu
Solid State and Structural Chemistry Unit, Indian Institute of Science , Bangalore 560012, India.
J Phys Chem Lett. 2018 Feb 15;9(4):696-701. doi: 10.1021/acs.jpclett.7b03190. Epub 2018 Jan 30.
While several potential applications of CuFeS quantum dots have already been reported, doubts regarding their optical and physical properties persist. In particular, it is unclear if the quantum dot material is metallic, a degenerately doped semiconductor, or else an intrinsic semiconductor material. Here we examine the physical properties of CuFeS quantum dots in order to address this issue. Specifically, we study the bump that is observed in the optical spectra of these quantum dots at ∼500 nm. Using a combination of structural and optical characterization methods, ultrafast spectroscopy, as well as electronic structure calculations, we ascertain that the unusual purple color of CuFeS quantum dots as well the golden luster of CuFeS films arise from the existence of a plasmon resonance in these materials. While the presence of free carriers causes this material to resemble gold, surface treatments are also described to suppress the plasmon resonance altogether.
虽然已经报道了CuFeS量子点的几种潜在应用，但对其光学和物理性质仍存在疑问。特别是，尚不清楚量子点材料是金属、简并掺杂半导体，还是本征半导体材料。在此，我们研究CuFeS量子点的物理性质以解决这个问题。具体而言，我们研究了在这些量子点的光谱中于~500 nm处观察到的凸起。通过结合结构和光学表征方法、超快光谱以及电子结构计算，我们确定CuFeS量子点异常的紫色以及CuFeS薄膜的金色光泽源于这些材料中存在等离子体共振。虽然自由载流子的存在使这种材料类似金，但也描述了表面处理方法以完全抑制等离子体共振。
