Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0020, Japan.
Nanoscale. 2018 Jul 19;10(28):13368-13374. doi: 10.1039/c8nr01501e.
The broad absorption of light in the UV-Vis-NIR region and the size-based tunable photoluminescence color of semiconductor quantum dots make these tiny crystals one of the most attractive antennae in solar cells and phosphors in electrooptical devices. One of the primary requirements for such real-world applications of quantum dots is their stable and uniform distribution in optically transparent matrices. In this work, we prepare transparent thin films of polymer-quantum dot conjugates, where CdSe/ZnS quantum dots are uniformly distributed at high densities in a chitosan-polystyrene copolymer (CS-g-PS) matrix. Here, quantum dots in an aqueous solution are conjugated to the copolymer by a phase transfer reaction. With the stable conjugation of quantum dots to the copolymer, we prevent undesired phase separation between the two and aggregation of quantum dots. Furthermore, the conjugate allows us to prepare transparent thin films in which quantum dots are uniformly distributed at high densities. The CS-g-PS copolymer helps us in not only preserving the photoluminescence properties of quantum dots in the film but also rendering excellent photostability to quantum dots at the ensemble and single particle levels, making the conjugate a promising material for photoluminescence-based devices.
半导体量子点在紫外可见近红外区域的宽吸收和基于尺寸的可调光致发光颜色，使这些微小晶体成为太阳能电池中最具吸引力的天线和光电设备中的荧光粉之一。量子点在实际应用中的一个主要要求是它们在光学透明基质中的稳定和均匀分布。在这项工作中，我们制备了聚合物-量子点共轭物的透明薄膜，其中 CdSe/ZnS 量子点在壳聚糖-聚苯乙烯共聚物（CS-g-PS）基质中以高浓度均匀分布。在这里，水溶液中的量子点通过相转移反应与共聚物结合。通过将量子点与共聚物稳定结合，我们防止了两者之间的不期望的相分离和量子点的聚集。此外，该共轭物使我们能够制备透明薄膜，其中量子点以高浓度均匀分布。CS-g-PS 共聚物不仅有助于在薄膜中保持量子点的光致发光性质，而且还赋予量子点在整体和单粒子水平上优异的光稳定性，使该共轭物成为基于光致发光的器件的有前途的材料。
