硅量子点的荧光光谱性质及与微盘耦合的研究

发布时间：2018-04-19 06:56

本文选题：胶体量子点 + 微盘　；参考：《中国科学院大学(中国科学院物理研究所)》2017年硕士论文

【摘要】：硅量子点是一种准零维的半导体纳米材料,由于量子限制作用,发光效率高,明显不同于几乎不发光的硅体材料。此外,硅量子点还具有不含重金属元素、储量丰富、加工工艺成熟等优点,引起了研究者的广泛关注,有望在光电、光伏、生物标记、单光子源等领域发挥重要作用。我们研究了不同环境下的硅量子点的荧光光谱,并将量子点与微盘耦合,研究了微盘对量子点荧光光谱的增强作用,得到以下研究成果:1、我们研究了硅量子点荧光光谱对功率的响应曲线,通过高斯拟合,得到硅量子点荧光光谱的峰值能量和线宽,发现峰值能量随激光功率的增加发生蓝移,这是由于量子点的能态填充效应;线宽随功率增加而变窄,这是因为硅量子点存在两种发光机制,它们对激光功率响应不同导致的。2、我们利用低温微区共聚焦荧光显微扫描系统分析了与微盘耦合的量子点的荧光光谱,耦合后的量子点发光得到了明显的增强。荧光积分光谱的强度增强约35倍。通过分析我们认为增强的主要原因是微盘增强了量子点的收集效率。3、研究了硅量子点荧光光谱的动力学衰减过程。通过比较不同条件下衰减速率、峰值移动和线宽变化分析了硅量子点荧光衰减的原因。我们发现由于光氧化和光漂白作用,空气中的光衰减现象非常严重,真空中光漂白现象得到有效抑制,低温环境下光氧化和光漂白几乎完全抑制。
[Abstract]:Silicon quantum dots (QDs) are quasi-zero dimensional semiconductor nanomaterials. Due to the quantum limitation, the luminescence efficiency is high, which is obviously different from that of almost no luminescent silicon materials.In addition, silicon quantum dots (QDs) have many advantages, such as no heavy metal elements, abundant reserves, mature processing technology and so on, which have attracted wide attention of researchers and are expected to play an important role in photovoltaic, photovoltaic, biomarker, single photon source and other fields.We have studied the fluorescence spectra of silicon quantum dots in different environments, coupled the quantum dots with the microdisk, and studied the enhancement effect of the microdisk on the fluorescence spectra of the quantum dots.We obtained the following research result: 1, we studied the response curve of fluorescence spectrum of silicon quantum dot to power. By Gao Si fitting, we got the peak energy and linewidth of fluorescence spectrum of silicon quantum dot, and found that the peak energy of silicon quantum dot blue shifted with the increase of laser power.This is due to the filling effect of the energy states of quantum dots; the linewidth narrows with the increase of power, which is due to the existence of two luminescence mechanisms in silicon quantum dots.Due to their different response to laser power, the fluorescence spectra of quantum dots coupled with microdisk were analyzed by using a low temperature confocal fluorescence scanning system, and the luminescence of quantum dots was obviously enhanced.The intensity of the fluorescence integral spectrum is increased about 35 times.We consider that the main reason for the enhancement is that the microdisk enhances the collection efficiency of quantum dots, and the kinetic decay process of the fluorescence spectra of silicon quantum dots is studied.The reason of fluorescence decay of silicon quantum dots was analyzed by comparing the attenuation rate, peak shift and linewidth variation under different conditions.It is found that the phenomenon of light decay in air is very serious due to photooxidation and photobleaching, the phenomenon of photobleaching in vacuum is effectively suppressed, and photooxidation and photobleaching are almost completely inhibited at low temperature.
【学位授予单位】：中国科学院大学(中国科学院物理研究所)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O471.1

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