半導(dǎo)體量子點的研究:幻數(shù)尺寸、多模發(fā)射以及不同結(jié)構(gòu)的量子點
發(fā)布時間：2018-12-29 12:47
【摘要】：膠體量子點之所以能吸引如此多的注意力是因為它們在生物標(biāo)記、光伏、照明、激光、光催化、熱電及新一代微電子器件中的潛在應(yīng)用價值,這是過去幾十年對其優(yōu)化合成及光電性質(zhì)深入研究的結(jié)果。在所有半導(dǎo)體量子點材料中,CdSe作為其中的典型材料擁有膠體量子點研究中的諸多第一,包括第一種利用膠體化學(xué)合成的總體尺寸分布小于10%的量子點,第一種連接生物分子并用于生物標(biāo)記的膠體量子點,第一種將吸收和發(fā)光實驗數(shù)據(jù)與理論計算的能帶結(jié)構(gòu)數(shù)據(jù)進行系統(tǒng)對比的材料等。三元合金半導(dǎo)體量子點的組分和結(jié)構(gòu)都比二元的Ⅱ-Ⅵ族半導(dǎo)體量子點復(fù)雜,但是它們的光電性質(zhì)可以通過改變半導(dǎo)體組分來調(diào)節(jié),因此有可能提高吸收的同時改善其載流子輸運性能,以促進在特定實踐中的應(yīng)用。因此,在本論文中主要以CdSe基核殼結(jié)構(gòu)量子點及合金量子點為研究對象,采用非注入法可控制備了系列高效發(fā)光量子點；利用高溫注射法制備了多種合金及其核殼結(jié)構(gòu)量子點；研究了不同體系幻數(shù)尺寸量子點的合成；構(gòu)筑了多模發(fā)光量子點材料；探討了量子點的生長機制以及發(fā)光機理；研究了量子點的相轉(zhuǎn)移方法,對量子點熒光探針的應(yīng)用做了初步探索。具體研究內(nèi)容如下：在第一章中,首先簡單介紹了量子點的性質(zhì)、結(jié)構(gòu)與發(fā)光機理,然后進一步總結(jié)了人們近年來在半導(dǎo)體量子點合成與應(yīng)用方面的研究進展以及存在的問題,提出了本論文的選題意義和主要研究內(nèi)容。在第二章中,通過一種非注入方法,以O(shè)DE為溶劑,Se粉和Cd(SA)2為原料,合成了CdSe量子點。在合適的條件下可以觀察到幻數(shù)尺寸(magic-sized)的量子點的形成,而且這些量子點在相對低溫下展現(xiàn)出不尋常的連續(xù)生長模型。通過吸收光譜和發(fā)光光譜對CdSe量子點的生長動力學(xué)進行了研究,結(jié)果顯示Se粉的溶劑是納米晶成核的發(fā)生點和成核速率的限制因素。對比實驗證實,與傳統(tǒng)的高溫?zé)岱纸夥ê铣上啾?在非注入合成中量子點的生長呈現(xiàn)出迥異的動力學(xué)特征。用此非注入方法合成的量子點具有很高的結(jié)晶度,其熒光量子產(chǎn)率由原來的34%,利用ZnS鈍化包覆后提高到63%,若在CdSe核與ZnS鈍化層之間加入一層ZnSe過渡層,則具有核殼結(jié)構(gòu)的CdSe/ZnSe/ZnS量子點的熒光量子產(chǎn)率熒光量子產(chǎn)率可高達74%,這與許多高溫?zé)岱纸夥ㄖ苽涞牧孔狱c的發(fā)光水平相當(dāng)。然后,我們進一步通過原位注入合成及后續(xù)包覆制備了多模發(fā)光CdSe/CdS/ZnS核殼結(jié)構(gòu)量子點,并對其發(fā)光性質(zhì)進行了系統(tǒng)研究。在第三章中,主要研究了利用高溫注射法制備寬發(fā)射光譜覆蓋的、不同形貌的CdTeSe基核殼結(jié)構(gòu)量子點,系統(tǒng)研究了注入過程與反應(yīng)溫度的影響,并對生長機制做了合理探討。通過對比球形CdTeSe量子點及其不同核殼結(jié)構(gòu)量子點的3-D PL光譜,研究了不同鈍化方式的量子點發(fā)光對激發(fā)波長依賴性的影響。與CdSe/ZnSe/ZnS量子點中的ZnSe殼層結(jié)構(gòu)作用類似,CdTeSe/ZnSe/ZnS中的ZnSe層也扮演了重要角色：提供平滑的界面以及緩變的能帶結(jié)構(gòu)。最后,紅光發(fā)射的核殼結(jié)構(gòu)量子點被轉(zhuǎn)移到水相,并成功用于對大腸桿菌E. Coli 0-157和淋巴瘤細(xì)胞YAC-1的標(biāo)記研究。在第四章中,主要以工業(yè)溶劑N-235為溶劑,利用高溫注射法制備了低成本高效黃光-紅光發(fā)射的CdZnSe合金量子點、CdSe/ZnSe以及CdZnS和ZnS包覆的核殼結(jié)構(gòu)量子點,量子點的熒光量子效率達到94%。系統(tǒng)研究了量子點結(jié)構(gòu)與包覆條件對發(fā)光性質(zhì)的影響,并對生長機制做了合理探討。探索了一系列高溫下合成了幻數(shù)尺寸量子點的影響因素,通過改變表面配體濃度,優(yōu)化反應(yīng)溫度制備了幻數(shù)尺寸的CdSe/ZnSe和CdZnSe量子點。最后利用SiO2對量子點進行了包覆并得到了單顆粒分散的量子點,SiO2包覆的量子點溶于水和多種緩沖溶液并保持長時間的穩(wěn)定性。在第五章中,主要對本論文的工作進行了總結(jié),分析和討論了現(xiàn)有研究工作存在的問題,并對未來的工作進行了展望�？傊�,基于本論文的研究工作,實現(xiàn)了基于非注入合成制備高效綠色發(fā)光量子點,基于高溫?zé)岱纸夥磻?yīng)制備了熒光量子產(chǎn)率達94%的黃紅色發(fā)光量子點,證明了通過合理調(diào)節(jié)加熱速率及前驅(qū)體濃度或表面配體用量及反應(yīng)溫度能夠在低溫非注入合成和高溫?zé)岱纸夥磻?yīng)中制備幻數(shù)尺寸量子點,通過調(diào)節(jié)反應(yīng)溫度與硅烷濃度可以實現(xiàn)單分散量子點的Si02包覆,本項研究對深入了解量子點合成中的動力學(xué)過程及拓展現(xiàn)有量子點應(yīng)用范圍具有極其重要的意義。
[Abstract]:Colloidal quantum dots can attract so much attention because of their potential application in biomarkers, photovoltaic, lighting, laser, photocatalysis, thermoelectric and a new generation of micro-electronic devices, which is the result of an in-depth study of its optimization and photo-electrical properties over the last few decades. In all semiconductor quantum dot materials, CdSe, as a typical material in which CdSe has a number of first in a colloidal quantum dot study, comprises a first quantum dot having a total size distribution of less than 10% by the first chemical synthesis, The first is a colloidal quantum dot to which a biological molecule is attached and used for a biological marker, a first material for comparing the absorption and luminescence experimental data with the theoretical calculated energy band structure data, and the like. The components and structures of the ternary alloy semiconductor quantum dots are more complex than the binary II-VI group semiconductor quantum dots, but their photoelectric properties can be adjusted by changing the semiconductor components, so that the absorption can be improved while the carrier transport performance is improved, to facilitate the application in a particular practice. In this paper, the quantum dots and the alloy quantum dots of the CdSe-based nuclear shell structure are mainly used as the research object, and a series of high-efficiency light-emitting quantum dots are prepared by adopting a non-injection method, and a plurality of alloys and a nuclear shell structure quantum dot are prepared by the high-temperature injection method; The synthesis of the quantum dots of the magic number of different systems is studied, the multi-mode light-emitting quantum dot material is constructed, the growth mechanism and the light-emitting mechanism of the quantum dots are discussed, the phase transfer method of the quantum dots is studied, and the application of the quantum dot fluorescent probe is explored. The specific research contents are as follows: In the first chapter, the properties, structure and light-emitting mechanism of the quantum dots are briefly introduced, and the research progress and existing problems in the synthesis and application of the semiconductor quantum dots in recent years are further summarized. The topic meaning and main research contents of this thesis are put forward. In the second chapter, CdSe quantum dots were synthesized by a non-injection method using ODE as solvent, Se powder and Cd (SA) 2 as raw materials. The formation of magic-sized quantum dots can be observed under appropriate conditions, and these quantum dots exhibit an unusual continuous growth model at relatively low temperatures. The growth kinetics of CdSe quantum dots is studied by absorption spectrum and luminescence spectrum. The results show that the solvent of Se powder is the limiting factor of the nucleation rate and the nucleation rate. Compared with the traditional high-temperature thermal decomposition method, the growth of the quantum dots in the non-injection synthesis has different dynamic characteristics compared with the traditional high-temperature thermal decomposition method. the quantum dots synthesized by the non-injection method have high crystallinity, the fluorescence quantum yield of the quantum dots is increased to 63 percent by using the ZnS passivation coating, and if a layer of ZnSe transition layer is added between the CdSe core and the ZnS passivation layer, The fluorescence quantum yield of the CdSe/ ZnSe/ ZnS quantum dots with the nuclear shell structure can be up to 74%, which is comparable to that of the quantum dots prepared by many high-temperature thermal decomposition methods. Then, the quantum dots of the multi-mode light-emitting CdSe/ CdS/ ZnS core shell structure are prepared by in-situ injection synthesis and subsequent coating, and the light-emitting properties of the multi-mode light-emitting CdSe/ CdS/ ZnS core shell structure are systematically studied. In the third chapter, the quantum dot of CdTeSe-based nuclear shell structure with wide emission spectrum and different morphology was studied by high-temperature injection method. The effect of injection process and reaction temperature was studied, and the mechanism of growth was discussed. The effect of quantum dot luminescence on the excitation wavelength dependence of different passivation methods was studied by comparing the 3-D PL spectra of the spherical CdTeSe quantum dots and the quantum dots of different core shell structures. Similar to the structure of the ZnSe shell layer in the CdSe/ ZnSe/ ZnS quantum dots, the ZnSe layer in the CdTeSe/ ZnSe/ ZnS also plays an important role in providing a smooth interface and a slowly varying energy band structure. Finally, the quantum dots of the nuclear shell structure emitted from red light were transferred to the aqueous phase and successfully used to study the labeling of E. Coli 0-157 and the lymphoma cell YAC-1. In the fourth chapter, the quantum dots of CdZnSe, CdSe/ ZnSe and CdZnS and ZnS-coated nuclear shell structures with low cost and high efficiency yellow light-red light are prepared by high-temperature injection, and the quantum efficiency of the quantum dots is 94%. The effect of quantum dot structure and coating conditions on the properties of light-emitting was studied, and the mechanism of growth was discussed. In this paper, the influence factors of the quantum dots of the magic number are synthesized under a series of high temperatures, and the CdSe/ ZnSe and CdZnSe quantum dots of the magic number size are prepared by changing the surface ligand concentration and optimizing the reaction temperature. and finally, the quantum dots with the single particle dispersion are coated by using the SiO2, and the quantum dots coated by the SiO2 are dissolved in water and a plurality of buffer solutions and are kept for a long time. In the fifth chapter, the work of the thesis is summarized, the problems existing in the existing research work are analyzed and discussed, and the future work is expected. In conclusion, based on the research work of this paper, a high-efficiency green light emitting quantum dot is prepared based on the non-injection synthesis, and the yellow-red light emitting quantum dot with the fluorescence quantum yield of 94% is prepared based on the high-temperature thermal decomposition reaction. in that invention, by reasonably adjust the heating rate and the precursor concentration or the amount of the surface ligand and the reaction temperature, the magic number size quantum dot can be prepared in the low-temperature non-injection synthesis and the high-temperature thermal decomposition reaction, and the Si02 coating of the monodisperse quantum dot can be realized by adjusting the reaction temperature and the silane concentration, This study is of great significance to the deep understanding of the dynamic process in the synthesis of quantum dots and to extend the application range of the existing quantum dots.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：O611.2
本文編號：2394844
[Abstract]:Colloidal quantum dots can attract so much attention because of their potential application in biomarkers, photovoltaic, lighting, laser, photocatalysis, thermoelectric and a new generation of micro-electronic devices, which is the result of an in-depth study of its optimization and photo-electrical properties over the last few decades. In all semiconductor quantum dot materials, CdSe, as a typical material in which CdSe has a number of first in a colloidal quantum dot study, comprises a first quantum dot having a total size distribution of less than 10% by the first chemical synthesis, The first is a colloidal quantum dot to which a biological molecule is attached and used for a biological marker, a first material for comparing the absorption and luminescence experimental data with the theoretical calculated energy band structure data, and the like. The components and structures of the ternary alloy semiconductor quantum dots are more complex than the binary II-VI group semiconductor quantum dots, but their photoelectric properties can be adjusted by changing the semiconductor components, so that the absorption can be improved while the carrier transport performance is improved, to facilitate the application in a particular practice. In this paper, the quantum dots and the alloy quantum dots of the CdSe-based nuclear shell structure are mainly used as the research object, and a series of high-efficiency light-emitting quantum dots are prepared by adopting a non-injection method, and a plurality of alloys and a nuclear shell structure quantum dot are prepared by the high-temperature injection method; The synthesis of the quantum dots of the magic number of different systems is studied, the multi-mode light-emitting quantum dot material is constructed, the growth mechanism and the light-emitting mechanism of the quantum dots are discussed, the phase transfer method of the quantum dots is studied, and the application of the quantum dot fluorescent probe is explored. The specific research contents are as follows: In the first chapter, the properties, structure and light-emitting mechanism of the quantum dots are briefly introduced, and the research progress and existing problems in the synthesis and application of the semiconductor quantum dots in recent years are further summarized. The topic meaning and main research contents of this thesis are put forward. In the second chapter, CdSe quantum dots were synthesized by a non-injection method using ODE as solvent, Se powder and Cd (SA) 2 as raw materials. The formation of magic-sized quantum dots can be observed under appropriate conditions, and these quantum dots exhibit an unusual continuous growth model at relatively low temperatures. The growth kinetics of CdSe quantum dots is studied by absorption spectrum and luminescence spectrum. The results show that the solvent of Se powder is the limiting factor of the nucleation rate and the nucleation rate. Compared with the traditional high-temperature thermal decomposition method, the growth of the quantum dots in the non-injection synthesis has different dynamic characteristics compared with the traditional high-temperature thermal decomposition method. the quantum dots synthesized by the non-injection method have high crystallinity, the fluorescence quantum yield of the quantum dots is increased to 63 percent by using the ZnS passivation coating, and if a layer of ZnSe transition layer is added between the CdSe core and the ZnS passivation layer, The fluorescence quantum yield of the CdSe/ ZnSe/ ZnS quantum dots with the nuclear shell structure can be up to 74%, which is comparable to that of the quantum dots prepared by many high-temperature thermal decomposition methods. Then, the quantum dots of the multi-mode light-emitting CdSe/ CdS/ ZnS core shell structure are prepared by in-situ injection synthesis and subsequent coating, and the light-emitting properties of the multi-mode light-emitting CdSe/ CdS/ ZnS core shell structure are systematically studied. In the third chapter, the quantum dot of CdTeSe-based nuclear shell structure with wide emission spectrum and different morphology was studied by high-temperature injection method. The effect of injection process and reaction temperature was studied, and the mechanism of growth was discussed. The effect of quantum dot luminescence on the excitation wavelength dependence of different passivation methods was studied by comparing the 3-D PL spectra of the spherical CdTeSe quantum dots and the quantum dots of different core shell structures. Similar to the structure of the ZnSe shell layer in the CdSe/ ZnSe/ ZnS quantum dots, the ZnSe layer in the CdTeSe/ ZnSe/ ZnS also plays an important role in providing a smooth interface and a slowly varying energy band structure. Finally, the quantum dots of the nuclear shell structure emitted from red light were transferred to the aqueous phase and successfully used to study the labeling of E. Coli 0-157 and the lymphoma cell YAC-1. In the fourth chapter, the quantum dots of CdZnSe, CdSe/ ZnSe and CdZnS and ZnS-coated nuclear shell structures with low cost and high efficiency yellow light-red light are prepared by high-temperature injection, and the quantum efficiency of the quantum dots is 94%. The effect of quantum dot structure and coating conditions on the properties of light-emitting was studied, and the mechanism of growth was discussed. In this paper, the influence factors of the quantum dots of the magic number are synthesized under a series of high temperatures, and the CdSe/ ZnSe and CdZnSe quantum dots of the magic number size are prepared by changing the surface ligand concentration and optimizing the reaction temperature. and finally, the quantum dots with the single particle dispersion are coated by using the SiO2, and the quantum dots coated by the SiO2 are dissolved in water and a plurality of buffer solutions and are kept for a long time. In the fifth chapter, the work of the thesis is summarized, the problems existing in the existing research work are analyzed and discussed, and the future work is expected. In conclusion, based on the research work of this paper, a high-efficiency green light emitting quantum dot is prepared based on the non-injection synthesis, and the yellow-red light emitting quantum dot with the fluorescence quantum yield of 94% is prepared based on the high-temperature thermal decomposition reaction. in that invention, by reasonably adjust the heating rate and the precursor concentration or the amount of the surface ligand and the reaction temperature, the magic number size quantum dot can be prepared in the low-temperature non-injection synthesis and the high-temperature thermal decomposition reaction, and the Si02 coating of the monodisperse quantum dot can be realized by adjusting the reaction temperature and the silane concentration, This study is of great significance to the deep understanding of the dynamic process in the synthesis of quantum dots and to extend the application range of the existing quantum dots.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：O611.2
【共引文獻】
相關(guān)碩士學(xué)位論文 前1條
1 謝蕓蕓;中國黃土地區(qū)地下水高砷形成機制研究[D];合肥工業(yè)大學(xué);2013年
，本文編號：2394844
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