本文關(guān)鍵詞： 苯并噻唑鹽衍生物 Z掃描 反飽和吸收 泵浦探測(cè)技術(shù) 瞬態(tài)吸收譜　出處：《哈爾濱工業(yè)大學(xué)》2017年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：非線性光學(xué)的快速發(fā)展離不開(kāi)非線性光學(xué)材料的支持,合理的設(shè)計(jì)和優(yōu)化材料成為人們關(guān)注的焦點(diǎn)。苯并噻唑鹽類(lèi)表現(xiàn)出強(qiáng)的非線性吸收響應(yīng),是很好的非線性光學(xué)材料。它有好的熒光特性和強(qiáng)的吸電子能力,在顯示、照明以及染料太陽(yáng)能電池中具有好的應(yīng)用前景。本論文對(duì)三種不同取代基的苯并噻唑鹽進(jìn)行研究,通過(guò)量子化學(xué)計(jì)算中的密度泛函理論方法,計(jì)算能級(jí)寬度和前線軌道的貢獻(xiàn)變化,對(duì)比發(fā)現(xiàn)取代基為咔唑的苯并噻唑分子電荷轉(zhuǎn)移能力強(qiáng)。利用可調(diào)諧的飛秒激光進(jìn)行不同波長(zhǎng)的Z掃描實(shí)驗(yàn)來(lái)研究三種分子電荷轉(zhuǎn)移對(duì)三階非線性的影響。三種分子溶液在600-800 nm表現(xiàn)出反飽和吸收現(xiàn)象,再用不同能量下的Z掃描實(shí)驗(yàn)確定反飽和吸收的機(jī)制是雙光子誘導(dǎo)激發(fā)態(tài)吸收,并通過(guò)理論分析,數(shù)據(jù)擬合得到相應(yīng)的物理參數(shù),數(shù)據(jù)結(jié)果表明,取代基為咔唑的苯并噻唑鹽三階非線性效應(yīng)最強(qiáng)。三種分子溶液在532 nm Z掃描實(shí)驗(yàn)表現(xiàn)出不同的非線性現(xiàn)象,取代基為苯環(huán)的苯并噻唑鹽表現(xiàn)出飽和向反飽和吸收轉(zhuǎn)換,結(jié)合飛秒泵浦探測(cè)技術(shù),解釋了其轉(zhuǎn)化的原因。最后通過(guò)皮秒簡(jiǎn)并泵浦探測(cè)技術(shù)和瞬態(tài)吸收譜,研究三種不同取代基的苯并噻唑鹽激發(fā)態(tài)吸收特性,確定分子的能級(jí)結(jié)構(gòu)以及速率方程,結(jié)合皮秒Z掃描實(shí)驗(yàn)確定了各能級(jí)的物理參數(shù)。分析對(duì)比三種分子材料的激發(fā)態(tài)壽命,發(fā)現(xiàn)通過(guò)合理的改變有機(jī)分子的取代基可以調(diào)控激發(fā)態(tài)壽命,這表明苯并噻唑鹽衍生物在非線性光學(xué)器件應(yīng)用中具有巨大的潛力。
[Abstract]:The rapid development of nonlinear optics can not be separated from the support of nonlinear optical materials. Reasonable design and optimization of materials have become the focus of attention. Benzothiazole salts exhibit strong nonlinear absorption response. It is a good nonlinear optical material. It has good fluorescence properties and strong electron absorption ability. It has a good application prospect in display, illumination and dye solar cells. In this paper, three kinds of benzothiazole salts with different substituents are studied. The energy level width and the contribution of the frontier orbit are calculated by using the density functional theory method in quantum chemical calculation. The charge transfer ability of benzothiazole with carbazole substituent was found to be strong. The effects of three molecular charge transfer on the third order nonlinearity were studied by using tunable femtosecond laser at different wavelengths. The molecular solution exhibits reverse saturation absorption at 600-800 nm. The mechanism of reverse saturation absorption is found to be two-photon induced excited state absorption by using Z-scan experiments with different energies. The corresponding physical parameters are obtained by theoretical analysis, and the results show that the two photon induced excited state absorption is the main mechanism of anti-saturation absorption, and the corresponding physical parameters are obtained by theoretical analysis. The third order nonlinear effect of benzothiazole salts with carbazole substituents was the strongest. The three kinds of molecular solutions showed different nonlinear phenomena in 532nm Z scanning experiments. The benzothiazolium salts with benzothiazolium substituents as benzene rings showed a saturation to reverse saturation absorption transition. Combined with femtosecond pumping detection technology, the reason of its conversion is explained. Finally, the excited state absorption characteristics of three benzothiazole salts with different substituents are studied by picosecond degenerate pump detection technique and transient absorption spectrum. The energy level structure and rate equation of the molecule are determined. The physical parameters of each energy level are determined by picosecond Z scan experiment. The excited state lifetime of three kinds of molecular materials is analyzed and compared. It is found that the lifetime of excited states can be controlled by changing the substituents of organic molecules reasonably, which indicates that benzothiazolium derivatives have great potential in the application of nonlinear optical devices.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：O626.25;O437
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本文編號(hào)：1518388