Laboratoire Kastler Brossel, UPMC-Sorbonne Universités, CNRS, ENS-PSL Research University, Collège de France , 4, Place Jussieu Case 74, F-75005 Paris, France.
Center for Disruptive Photonic Technology (CDPT), School of Physical and Mathematical Sciences (SPMS), Nanyang Technological University , 21 Nanyang Link, Singapore 637371, Singapore.
ACS Nano. 2015 Aug 25;9(8):7992-8003. doi: 10.1021/acsnano.5b01354. Epub 2015 Jul 31.
We present a method that allows determining the band-edge exciton fine structure of CdSe/CdS dot-in-rods samples based on single particle polarization measurements at room temperature. We model the measured emission polarization of such single particles considering the fine structure properties, the dielectric effect induced by the anisotropic shell, and the measurement configuration. We use this method to characterize the band-edge exciton fine structure splitting of various samples of dot-in-rods. We show that, when the diameter of the CdSe core increases, a transition from a spherical like band-edge exciton symmetry to a rod-like band edge exciton symmetry occurs. This explains the often reported large emission polarization of such particles compared to spherical CdSe/CdS emitters.
我们提出了一种方法，可基于室温下单粒子偏振测量来确定 CdSe/CdS 点-棒样品的能带边激子精细结构。我们通过考虑精细结构特性、各向异性壳引起的介电效应以及测量配置，对这种单粒子的测量发射偏振进行建模。我们使用这种方法来对各种点-棒样品的带边激子精细结构分裂进行特征描述。我们表明，当 CdSe 核的直径增加时，会从球形的带边激子对称性过渡到棒状的带边激子对称性。这解释了与球形 CdSe/CdS 发射器相比，这种粒子通常具有较大的发射偏振。
