發(fā)布時(shí)間：2018-04-22 05:12

  本文選題：碳量子點(diǎn) + 光致發(fā)光�。� 參考：《太原理工大學(xué)》2017年碩士論文

【摘要】：碳量子點(diǎn)(Carbon quantum dots,CQDs)是一類(lèi)主要由碳、氫、氧組成、粒徑小于10 nm、表面富含官能團(tuán)、具有熒光性能的準(zhǔn)零維碳納米粒子。CQDs具有易修飾、熒光范圍可調(diào)、綠色環(huán)保、制備成本低等優(yōu)異特性,目前已在生物成像、光學(xué)傳感器、光催化、化學(xué)傳感器及光電領(lǐng)域獲得應(yīng)用。本論文開(kāi)展CQDs制備及CQDs在發(fā)光器件應(yīng)用領(lǐng)域的研究,即利用其光致發(fā)光和電致發(fā)光性質(zhì)作為熒光粉材料和發(fā)光層材料分別應(yīng)用于光致發(fā)光二極管(Light-emitting diode,LED)和量子點(diǎn)基電致發(fā)光二極管(Quantum dots-based LED,QLED)。目前,基于CQDs的LED和QLED器件仍存在一些問(wèn)題:一方面,CQDs作為L(zhǎng)ED的熒光粉材料主要存在熒光量子產(chǎn)率低、紅綠藍(lán)光譜比重低、粘接劑中分散性差的問(wèn)題,會(huì)導(dǎo)致LED器件的發(fā)光性能較差;另一方面,CQDs作為QLED的發(fā)光層材料是量子點(diǎn)電致發(fā)光應(yīng)用的一種新的嘗試,主要存在熒光量子產(chǎn)率低、電荷傳輸性能差、器件制備工藝復(fù)雜的問(wèn)題。因此,本論文旨在制備熒光量子產(chǎn)率高、紅綠藍(lán)光譜比重高、可直接成膜的單一基質(zhì)CQDs熒光粉以及良好電荷傳輸性能的CQDs發(fā)光層材料,并分別將其應(yīng)用于白光LED和QLED。具體研究?jī)?nèi)容和結(jié)果包括以下兩方面:1、以一水合檸檬酸為碳源、硅烷偶聯(lián)劑KH-792為添加劑,采用一步水熱法制備了熒光量子產(chǎn)率為57.3%、紅綠藍(lán)光譜比重為60.1%、粒徑為2.5-3.5 nm且具有激發(fā)獨(dú)立性的有機(jī)硅烷功能化CQDs。該CQDs水溶液在簡(jiǎn)單的熱處理?xiàng)l件下表現(xiàn)出可直接成膜的能力。將該單一基質(zhì)CQDs熒光膜結(jié)合紫外LED芯片制作了白光LED器件。此白光LED器件發(fā)冷白光,色坐標(biāo)為(0.31,0.36),相關(guān)色溫為6282 K,顯色指數(shù)為84。另外,該器件在不同的工作電壓及不同的工作時(shí)間間隔下都表現(xiàn)出良好的光穩(wěn)定性。因此,選擇多羧基、羥基的有機(jī)酸為碳源,同時(shí)引入氮原子的反應(yīng)體系能夠制得高QY和RGB光譜比重的CQDs。選擇可起粘接劑作用的添加劑,能夠制得可溶液直接成膜的CQDs體系,從而應(yīng)用于LED器件。2、以鄰苯二甲酸為碳源、乙二胺為添加劑,采用一步水熱法制備了熒光量子產(chǎn)率為29.3%且具有激發(fā)依賴(lài)性的CQDs。該CQDs顆粒分散性良好,粒徑大小在4-7 nm之間,具有一定的晶體結(jié)構(gòu),晶面間距為0.22 nm。將其作為發(fā)光層材料結(jié)合有機(jī)功能層材料PEDOT:PSS空穴傳輸層、TPBI電子傳輸層制作了QLED器件,考察了不同的CQDs旋涂用量、旋涂轉(zhuǎn)速及旋涂時(shí)間對(duì)器件性能的影響。結(jié)果表明:當(dāng)CQDs旋涂用量為360μL、旋涂轉(zhuǎn)速為1000 rpm、旋涂時(shí)間為30 s時(shí),器件發(fā)藍(lán)光,其亮度達(dá)到4.9 cd/m2,啟亮電壓為5.5 V。因此,選擇含芳環(huán)結(jié)構(gòu)的碳源可制得具有一定結(jié)晶程度的CQDs。QLED器件的性能不僅受CQDs發(fā)光層材料自身性質(zhì)的影響,還受器件結(jié)構(gòu)、發(fā)光層厚度等的影響。
[Abstract]:Carbon quantum Dots (C QDs) is a class of quasi zero dimensional carbon nanoparticles. CQDs are mainly composed of carbon, hydrogen and oxygen, with particle size less than 10 nm, and the surface is rich in functional groups. CQDs have the advantages of easy modification, adjustable fluorescence range and green environmental protection. At present, it has been applied in the fields of biological imaging, optical sensor, photocatalysis, chemical sensor and photoelectricity. In this thesis, the preparation of CQDs and the application of CQDs in luminescent devices are studied. That is to say, the photoluminescence and electroluminescent properties are used as phosphors and photoluminescence layer materials for Light-emitter diodes (LEDs) and Quantum dots-based LEDs (QLEDs), respectively. At present, there are still some problems in LED and QLED devices based on CQDs: on the one hand, as phosphors of LED, there are many problems such as low fluorescence quantum yield, low spectral proportion of red, green and blue, and poor dispersion in adhesives. On the other hand, it is a new attempt in the application of quantum dot electroluminescence that the photoluminescence properties of LED devices are low, and the charge transport performance is poor. Complex process of device preparation. Therefore, the aim of this thesis is to prepare single substrate CQDs phosphor with high fluorescence quantum yield, red green blue spectral specific gravity, direct film formation and CQDs luminescent layer with good charge transport performance, and to apply them to white LED and QLED respectively. The specific research contents and results include the following two aspects: 1. Using citric acid monohydrate as carbon source and silane coupling agent KH-792 as additive. Organic silane functionalized CQDswere prepared by one-step hydrothermal method with fluorescence quantum yield of 57.3%, red, green and blue spectral specific gravity of 60.1 and particle size of 2.5-3.5 nm. The CQDs aqueous solution shows the ability to form films directly under simple heat treatment conditions. The white light LED device was fabricated by combining the single substrate CQDs fluorescent film with UV LED chip. The white LED device has a cool white light with a color coordinate of 0.31 ~ 0.36 ~ 0.36, a relative color temperature of 6282 K and a color-rendering index of 84. In addition, the device exhibits good optical stability under different operating voltages and time intervals. Therefore, the organic acids with multiple carboxyl groups and hydroxyl groups were selected as carbon source, and nitrogen atoms were introduced into the reaction system to produce CQDs with high spectral specific gravity of QY and RGB. The CQDs system, which can be directly film formed by solution, can be prepared by selecting the additive which can act as binder. The system can be used in LED device. 2. Phthalic acid is used as carbon source and ethylene diamine is used as additive. CQDs with a fluorescence quantum yield of 29.3% and excitation dependence were prepared by one-step hydrothermal method. The CQDs particles have good dispersibility, the particle size is between 4-7 nm and has a certain crystal structure, and the crystal plane spacing is 0.22 nm. QLED devices were fabricated by the combination of PEDOT:PSS hole transport layer and organic functional layer material. The effects of different CQDs spin-coating dosage, spin-coating speed and spin-coating time on the performance of the device were investigated. The results show that when the amount of CQDs spin coating is 360 渭 L, the spin coating speed is 1000 rpm, and the spin coating time is 30 s, the luminance of the device is 4.9 CD / m ~ (2) and the starting voltage is 5.5 V. Therefore, the properties of CQDs.QLED devices with a certain degree of crystallization can be obtained by selecting the carbon source with aromatic ring structure, which is influenced not only by the properties of the CQDs luminescent layer, but also by the structure of the device and the thickness of the luminescent layer.
【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(lèi)號(hào)】：TN312.8;O613.71

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本文編號(hào)：1785738