等离子体增强的局域激子产生、载流子扩散和增强的光子发射的主动介导

Active Mediation of Plasmon Enhanced Localized Exciton Generation, Carrier Diffusion and Enhanced Photon Emission.

作者信息

Haq Sharmin, Addamane Sadhvikas, Kafle Bijesh, Huang Danhong, Balakrishnan Ganesh, Habteyes Terefe G

机构信息

Optical Science & Engineering Program, University of New Mexico, Albuquerque, NM, 87131, United States.

Center for High Technology Materials, University of New Mexico, Albuquerque, NM, 87131, United States.

出版信息

Sci Rep. 2017 Apr 13;7(1):864. doi: 10.1038/s41598-017-00964-5.

DOI:10.1038/s41598-017-00964-5

PMID:28408765

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5429829/

Abstract

Understanding the enhancement of charge carrier generation and their diffusion is imperative for improving the efficiency of optoelectronic devices particularly infrared photodetectors that are less developed than their visible counterpart. Here, using gold nanorods as model plasmonic systems, InAs quantum dots (QDs) embedded in an InGaAs quantum well as an emitter, and GaAs as an active mediator of surface plasmons for enhancing carrier generation and photon emission, the distance dependence of energy transfer and carrier diffusion have been investigated both experimentally and theoretically. Analysis of the QD emission enhancement as a function of distance reveals a Förster radius of 3.85 ± 0.15 nm, a near-field decay length of 4.8 ± 0.1 nm and an effective carrier diffusion length of 64.0 ± 3.0 nm. Theoretical study of the temporal-evolution of the electron-hole occupation number of the excited states of the QDs indicates that the emission enhancement trend is determined by the carrier diffusion and capture rates.

摘要

对于提高光电器件的效率而言，理解电荷载流子的产生及其扩散增强至关重要，尤其是对于那些比可见光对应器件发展程度更低的红外光电探测器。在此，以金纳米棒作为模型等离子体系统，将嵌入InGaAs量子阱中的InAs量子点（QD）作为发射体，并将GaAs作为用于增强载流子产生和光子发射的表面等离子体的活性介质，通过实验和理论研究了能量转移和载流子扩散的距离依赖性。对作为距离函数的量子点发射增强的分析揭示了3.85±0.15nm的福斯特半径、4.8±0.1nm的近场衰减长度以及64.0±3.0nm的有效载流子扩散长度。对量子点激发态的电子 - 空穴占据数的时间演化的理论研究表明，发射增强趋势由载流子扩散和俘获率决定。