【作者】 高宝；

【导师】 许主国； 张浩力；

【作者基本信息】 兰州大学 ， 有机化学， 2013， 硕士

【摘要】 半导体量子点由于具有独特的电学和光学性质而受到了人们的广泛关注。这些性质包括可调节的光学吸收性质、较大的消光系数、高的光稳定性,这些性质为其在光电器件领域的应用奠定了的基础。PbS和PbSe是Ⅳ-Ⅵ族半导体化合物,具有较窄的带隙(PbS:0.41eV; PbSe:0.28eV)和较大的激子波尔半径(PbS:18nm; PbSe:46nm),因此在发光二极管、单电子晶体管、场效应晶体管、太阳能电池以及热电材料方面具有潜在的应用。本论文,我们主要开展了利用热注射的方式制备PbS、PbSe、PbSxSe1-x量子点,提出了一种简单的合成方法,得到了具有不同尺寸和形貌的量子点。在此基础上,我们研究了温度和反应时间对纳米粒子尺寸和形貌的影响,并探讨了它们的光学性质。本论文的主要工作如下：1.利用热注射法,合成了不同表面活性剂修饰的PbS量子点。分别研究了油酸、油胺、十六胺和对溴苯胺做表面修饰试剂时,实验温度和反应时间对量子点形貌和尺寸的影响。2.我们提出了一种新的PbSe量子点的合成方法。在本方法中,我们采用油胺作为唯一的表面活性剂和溶剂,得到尺寸均一、形貌可控的、球形和方形PbSe量子点。在此基础上,我们以十八烯作为溶剂,少量的油胺为表面活性剂,研究了不同温度和油胺的用量对PbSe纳米粒子形貌和尺寸的影响。3.我们在合成PbS、PbSe量子点的基础上,首次制备了油胺修饰的PbSxSe1-x三元量子点,并对其结构与组成的关系进行了研究。此外,我们研究了不同组成的三元量子点PbSxSe1-x的近红外吸收和光限幅性质。更多还原

【Abstract】 Semiconductor nanocrystals have attracted great research interest due to their unique optical and electrical properties. These properties include controllable optical absoption properties, large extinction coefficient, and extended photostability, which underlie extensive application in photoelectric device. PbS and PbSe are important Ⅳ-Ⅵ rock salt structure semiconductor materials with narrow band gap energy (PbS:0.41eV, PbSe:0.28eV) and large exciton Bohr radius (PbS:18nm, PbSe:46nm), whcih are useful in novel nanodevices such as light-emitting diodes, single electron transistors, field-effect thin-thim transistors, solar cell and thermoelectric material.The main finding of this thesis includes:1. We prepared PbS nanoparticles modified with different ligands. We studied the effects of temperature and reaction time on quantem dots’s size and morphology modified with oleylamine, oleic acid,1-hexadecanamine, parabromoaniline.2. We proposed a novel method for preparation of PbSe and obtained cubic and spherical PbSe nanocrystal modified with oleylamine. We also obtained high quality cubic and spherical PbSe nanocrystal under octadecene. We explored the effects of temperature and the amount of oleylamine on quantum dots’size and morphology.3. We fabricated PbSxSe1-x ternary nanoparticles on the basis of PbS and PbSe, and studied their structure and composition. We then studied near infrared absorption and optical limiting properties of ternary PbSxSe1-x quantem dots.更多还原