微納結(jié)構(gòu)提高熒光物質(zhì)發(fā)光強(qiáng)度的研究
發(fā)布時(shí)間：2018-07-26 16:22
【摘要】：隨著微納光子學(xué)科的蓬勃發(fā)展,各種多功能的微納光子結(jié)構(gòu)被設(shè)計(jì)和制備,并在醫(yī)療、通信和能源等方面得到應(yīng)用。增強(qiáng)熒光物質(zhì)的發(fā)光強(qiáng)度是微納光子結(jié)構(gòu)應(yīng)用的一個(gè)重要方面。LED是照明和顯示器件的核心器件。伴隨著量子點(diǎn)制備技術(shù)的發(fā)展,量子點(diǎn)LED被制備出來(lái),它比目前的LED在產(chǎn)生白光方面更有優(yōu)勢(shì),因此研究增強(qiáng)量子點(diǎn)的熒光有現(xiàn)實(shí)的意義。同時(shí),在生命科學(xué)領(lǐng)域,提高熒光檢測(cè)的靈敏度的意義重大,而提高熒光物質(zhì)的發(fā)光則是提高檢測(cè)靈敏度的重要前提。由于微納結(jié)構(gòu)的小尺寸,外界電磁波與其作用時(shí),能量密度主要集中在微納結(jié)構(gòu)的表面附近范圍。而實(shí)際的醫(yī)學(xué)應(yīng)用中,特別是對(duì)于體外細(xì)胞的測(cè)量,往往需要將熒光物質(zhì)置于結(jié)構(gòu)的遠(yuǎn)場(chǎng)范圍內(nèi)。因此增強(qiáng)熒光物質(zhì)在距離結(jié)構(gòu)遠(yuǎn)場(chǎng)區(qū)域的遠(yuǎn)場(chǎng)熒光對(duì)于在生物傳感方面有十分有必要�；谝陨系姆治�,為了提高量子點(diǎn)的發(fā)光光強(qiáng)并應(yīng)用于量子點(diǎn)白光LED,作者設(shè)計(jì)了一種周期性多層異質(zhì)結(jié)構(gòu)。采用嚴(yán)格耦合波分析法和有限時(shí)域差分法模擬了周期數(shù)、各層厚度、入射角度對(duì)反射率的影響,以及幾個(gè)特定波長(zhǎng)的電場(chǎng)分布。實(shí)現(xiàn)了多個(gè)高反射波段,分別對(duì)應(yīng)著紫外光、紫光、藍(lán)光、青光和紅光,且高反射波帶可調(diào)節(jié)。并且實(shí)驗(yàn)驗(yàn)證了該結(jié)構(gòu)可以實(shí)現(xiàn)量子點(diǎn)的熒光增強(qiáng)。其增強(qiáng)機(jī)理為結(jié)構(gòu)對(duì)入射光的多次反射和干涉效應(yīng)。為了提高熒光物質(zhì)在器件的遠(yuǎn)場(chǎng)發(fā)光,設(shè)計(jì)了一種半圓柱形金屬微米通道。研究了熒光激發(fā)過(guò)程中,兩種偏振模式下,在結(jié)構(gòu)空間相同一點(diǎn)(Point A)的時(shí)域和頻域變化。通過(guò)研究時(shí)域圖發(fā)現(xiàn),各個(gè)結(jié)構(gòu)都比對(duì)比的玻璃結(jié)構(gòu)更容易使得上轉(zhuǎn)化粒子被激發(fā);通過(guò)研究頻域圖發(fā)現(xiàn),在激發(fā)光980 nm(上轉(zhuǎn)換粒子的激發(fā)光波長(zhǎng))時(shí),半圓形的金屬凹槽結(jié)構(gòu)在Point A點(diǎn)光最強(qiáng)。研究了熒光發(fā)射過(guò)程,將熒光物質(zhì)放置在空間中相同位置(Point A),測(cè)量遠(yuǎn)場(chǎng)的熒光強(qiáng)度,發(fā)現(xiàn)半圓柱形的金屬凹槽結(jié)構(gòu)的遠(yuǎn)場(chǎng)熒光最強(qiáng)。測(cè)量波長(zhǎng)為617 nm時(shí),幾種典型結(jié)構(gòu)的電場(chǎng)分布圖,以及熒光物質(zhì)放在不同位置時(shí),半圓形金屬凹槽結(jié)構(gòu)的電場(chǎng)分布圖。并通過(guò)研究熒光物質(zhì)在該結(jié)構(gòu)的不同位置的遠(yuǎn)場(chǎng)熒光強(qiáng)度。最終結(jié)果表明,該結(jié)構(gòu)與玻璃平板結(jié)構(gòu)相比,實(shí)現(xiàn)了處于其距離結(jié)構(gòu)底部4.4微米處的上轉(zhuǎn)換納米粒子的遠(yuǎn)場(chǎng)熒光增強(qiáng)倍數(shù)為8.25。其增強(qiáng)機(jī)理為在結(jié)構(gòu)樣品區(qū)中復(fù)雜的散射、相干干涉和光耦合模式從而導(dǎo)致了熒光的增強(qiáng)。設(shè)計(jì)了一種新型微腔結(jié)構(gòu),基底采用的是五個(gè)周期的Si和SiO2,并水平方向放置兩個(gè)Ag的反射板。計(jì)算了該結(jié)構(gòu)和其它三個(gè)結(jié)構(gòu)的熒光發(fā)射過(guò)程,并對(duì)比了遠(yuǎn)場(chǎng)的發(fā)光光強(qiáng),證明了該結(jié)構(gòu)具有熒光增強(qiáng)效應(yīng)。通過(guò)對(duì)波長(zhǎng)為656 nm處的電場(chǎng)分析,可以知道熒光物質(zhì)與結(jié)構(gòu)的耦合模式較強(qiáng)。
[Abstract]:With the rapid development of micro-nano photonics, a variety of multi-functional micro-nano photonic structures have been designed and fabricated, and have been applied in medical, communication and energy fields. Enhanced luminescence intensity of fluorescent materials is an important aspect of the application of micro-nano photonic structure. Led is the core device of lighting and display devices. With the development of quantum dot preparation technology, quantum dot LED has been prepared, which is superior to the current LED in the generation of white light. Therefore, it is of practical significance to study the enhancement of quantum dot fluorescence. At the same time, in the field of life science, it is very important to improve the sensitivity of fluorescence detection, and to improve the luminescence of fluorescent substances is an important prerequisite to improve the sensitivity of detection. Due to the small size of micro / nano structure, the energy density is mainly near the surface of micro / nano structure when external electromagnetic waves interact with it. In practical medical applications, especially for the measurement of cells in vitro, fluorescent substances often need to be placed in the far-field range of the structure. Therefore, it is necessary to enhance the far field fluorescence of fluorescent substance in the far field region of the structure. Based on the above analysis, in order to improve the luminous intensity of quantum dots and apply to white LED, a periodic multilayer heterostructure is designed. The effects of period number, thickness of each layer and incident angle on reflectivity and electric field distribution of several specific wavelengths are simulated by means of strictly coupled wave analysis and finite-time-domain difference method. Several high reflectance bands are realized, corresponding to UV, UV, blue, blue and red, respectively, and the high reflectance band is adjustable. The experimental results show that the structure can enhance the fluorescence of quantum dots. The enhancement mechanism is the multiple reflection and interference effect of the structure to the incident light. In order to improve the far-field luminescence of the device, a semi-cylindrical metal micron channel is designed. The time-domain and frequency-domain variations of (Point A) at the same point in structure space in two polarization modes during fluorescence excitation are studied. By studying the time domain map, it is found that each structure is easier to excite the upconversion particle than the contrast glass structure, and the frequency domain diagram shows that when the excitation light is 980 nm (the excitation wavelength of the up-converted particle), The semicircular metal grooves have the strongest light at Point A. The fluorescence emission process was studied. The fluorescence intensity was measured by (Point A), at the same position in the space. It was found that the far field fluorescence of the semicircular metal groove structure was the strongest. When the wavelength is 617 nm, the electric field distribution of several typical structures and the electric field distribution of semicircular metal grooves are obtained. The far field fluorescence intensity of the fluorescent substance at different positions of the structure was studied. The final results show that compared with the glass plate structure, the far-field fluorescence enhancement multiple of the up-converted nanoparticles located at 4.4 渭 m from the bottom of the structure is 8.25. The enhancement mechanism is complicated scattering, coherent interference and optical coupling mode in the structural sample region, which leads to fluorescence enhancement. A new type of microcavity structure is designed. The substrate is Si and Sio _ 2 with five periods and two Ag reflective plates are placed horizontally. The fluorescence emission process of the structure and the other three structures are calculated, and the luminescence intensity in the far field is compared. It is proved that the structure has fluorescence enhancement effect. By analyzing the electric field at the wavelength of 656 nm, we can know that the coupling mode between the fluorescence substance and the structure is strong.
【學(xué)位授予單位】：太原理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O657.3
，
本文編號(hào)：2146580
[Abstract]:With the rapid development of micro-nano photonics, a variety of multi-functional micro-nano photonic structures have been designed and fabricated, and have been applied in medical, communication and energy fields. Enhanced luminescence intensity of fluorescent materials is an important aspect of the application of micro-nano photonic structure. Led is the core device of lighting and display devices. With the development of quantum dot preparation technology, quantum dot LED has been prepared, which is superior to the current LED in the generation of white light. Therefore, it is of practical significance to study the enhancement of quantum dot fluorescence. At the same time, in the field of life science, it is very important to improve the sensitivity of fluorescence detection, and to improve the luminescence of fluorescent substances is an important prerequisite to improve the sensitivity of detection. Due to the small size of micro / nano structure, the energy density is mainly near the surface of micro / nano structure when external electromagnetic waves interact with it. In practical medical applications, especially for the measurement of cells in vitro, fluorescent substances often need to be placed in the far-field range of the structure. Therefore, it is necessary to enhance the far field fluorescence of fluorescent substance in the far field region of the structure. Based on the above analysis, in order to improve the luminous intensity of quantum dots and apply to white LED, a periodic multilayer heterostructure is designed. The effects of period number, thickness of each layer and incident angle on reflectivity and electric field distribution of several specific wavelengths are simulated by means of strictly coupled wave analysis and finite-time-domain difference method. Several high reflectance bands are realized, corresponding to UV, UV, blue, blue and red, respectively, and the high reflectance band is adjustable. The experimental results show that the structure can enhance the fluorescence of quantum dots. The enhancement mechanism is the multiple reflection and interference effect of the structure to the incident light. In order to improve the far-field luminescence of the device, a semi-cylindrical metal micron channel is designed. The time-domain and frequency-domain variations of (Point A) at the same point in structure space in two polarization modes during fluorescence excitation are studied. By studying the time domain map, it is found that each structure is easier to excite the upconversion particle than the contrast glass structure, and the frequency domain diagram shows that when the excitation light is 980 nm (the excitation wavelength of the up-converted particle), The semicircular metal grooves have the strongest light at Point A. The fluorescence emission process was studied. The fluorescence intensity was measured by (Point A), at the same position in the space. It was found that the far field fluorescence of the semicircular metal groove structure was the strongest. When the wavelength is 617 nm, the electric field distribution of several typical structures and the electric field distribution of semicircular metal grooves are obtained. The far field fluorescence intensity of the fluorescent substance at different positions of the structure was studied. The final results show that compared with the glass plate structure, the far-field fluorescence enhancement multiple of the up-converted nanoparticles located at 4.4 渭 m from the bottom of the structure is 8.25. The enhancement mechanism is complicated scattering, coherent interference and optical coupling mode in the structural sample region, which leads to fluorescence enhancement. A new type of microcavity structure is designed. The substrate is Si and Sio _ 2 with five periods and two Ag reflective plates are placed horizontally. The fluorescence emission process of the structure and the other three structures are calculated, and the luminescence intensity in the far field is compared. It is proved that the structure has fluorescence enhancement effect. By analyzing the electric field at the wavelength of 656 nm, we can know that the coupling mode between the fluorescence substance and the structure is strong.
【學(xué)位授予單位】：太原理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O657.3
，
本文編號(hào)：2146580
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