【作者】 张静； 杨倩； 曹红； Frank S.Riehle； 余睽；

【Author】 Jing Zhang;Qian,yang;Hong Cao;Frank S.Riehle;Kui Yu;Institute of Atomic and Molecular Physics, Sichuan University;National Research Council of Canada;

【机构】 四川大学原子与分子物理研究所； 加拿大国家研究院；

【摘要】 胶体半导体量子点以其独特的光学性质被广泛的应用于发光二极管（LED）、太阳能电池、生物医学等领域。本研究发展了一种低温高重现性的方法成功制备了高质量蓝绿色发光的Cd Se_x S_1-x合金量子点,能够在490 nm实现79%的绝对荧光量子产率。通过二苯基膦（PHPh₂,DPP）的使用同时控制高Cd/（Se+S）和S/Se摩尔比的方式有利于交换反应TOPE+DPP?TOP+EDPP向右进行,产生活性更高的前驱物DPPSe和DPPS。通过X射线衍射、透射电镜、X射线光电子能谱、¹¹³Cd固态核磁等手段揭示了该Cd Se_xS_1-x合金量子点具有一个富Se核层,Se-S含量相当的中间层和富S外层的三层结构。我们的研究为二级膦的使用和低温高重现性制备三元合金量子点的合成提供了全新的认识。更多还原

【Abstract】 Colloidal semiconductor nanocrystals（NCs also called quantum dots（QDs）） has much potential in various areas such as light emitting devices（LED）, solar cell, and bio-imaging. Our study is aiming to develop a low-temperature and high synthetic reproducibility method to synthesis of gradient-alloyed Cd Se_xS_1-x QDs with highly cyan-blue emission. The use of secondary phosphines DPP together with high Cd/（Se + S） and S/Se feed molar ratio shift the chalcogenide exchange TOPE + DPP  TOP + E to the right, which can significantly increase the precursor reactivity. Powder X-ray diffraction（PXRD）, transmission electron microscopy（TEM）, energy dispersive X-ray spectroscopy（EDX）, X-ray photoelectron spectroscopy（XPS） were performed for the structural and compositional characterization. Particularly, solid-state ¹¹³Cd NMR analysis reveals that the highly emissive Cd Se S QDs consist of a three-domain structure with a Se-rich inner core region, a Se/S equivalent middle region, and a S-rich outer region. The present study highlights the importance on the use of secondary phosphines together with high cation/anion feed molar ratios in the rational design and synthesis of high-quality metal chalcogenide QDs at relatively low temperature but with high yield and reproducibility.更多还原