環保碳量子點應用於發光薄膜及螢光太陽能聚光板

Solution-processed, Eco-friendly Carbon Dots for Light-emitting Thin Films and Luminescent Solar Concentrators

姜智程(Zh-Cheng Jiang)

指導教授 ： 院繼祖

中原大學/理學院/物理研究所/碩士(2016年)

https://doi.org/10.6840/cycu201600622

摘要

近期，膠體碳量子點受到學者矚目，因為碳量子點擁有獨特材料和螢光特性，例如:大量且多樣的碳前驅物材料、低毒性、高螢光穩定性和螢光的可調性。然而碳量子點從水溶液轉換至固態時，因為聚集導致自我螢光淬滅使螢光強度與穩定性下降許多，為了解決上述的問題，我們製作出高效率的表面微米結構的碳量子點PVA發光薄膜。高分子聚合物PVA被選用來保護碳量子點以及均勻分散的載體，能夠提升內部量子產率至69%。表面微米結構可以使萃取被困住的光，減少因波導流失的螢光量，最後我們使光萃取效率提高兩倍。碳量子點薄膜不僅有上述的特點，也具備在高溫下(150℃)的螢光穩定性，因此它可以被應用在環保且低成的固態發光元件上。
到目前為止，大部分碳量子點合成法都是利用水當作反應溶劑，其中微波合成法就是一個典型利用水當作反應溶劑，因此碳量子點的表面含有許多親水性官能基。不幸的是，水溶性碳量子點難以應用在光電元件上，因為大部分的光電元件需要疏水性的材料來分散在有機溶劑。因此，我們合成出另外一種油溶性量子點，並利用此碳量子點製作出螢光太陽能聚光板，由油溶性碳量子與高分子聚合物PDMS結合的螢光太陽能聚光板，搭配在矽太陽能電池上，是未來零碳耗建築發展的一種要角色。

關鍵字

碳量子點 ； 發光薄膜 ； 螢光太陽能聚光板

並列摘要

Solution-processed carbon dots (CDs) have attracted much attention owing to their superior materials and photoluminescence (PL) properties, such as abundant precursor materials, less toxicity, high photo-stability and tunable emission. However, their PL properties, including PL quantum yields and photo-stability would be significantly degraded due to concentration-induced solid-state quenching and unstable surface. In this thesis, we fabricated high quality CDs/polyvinyl alcohol (PVA) light-emitting flexible films with submicron structure patterns by a facile and low cost method. PVA is chosen as the host matrix to both disperse and passivate CDs, leading to enhanced internal quantum yields (69%) in the solid states. Patterned CDs/PVA composite can be used to extract the trapped light, thus mitigate the waveguide-mode losses, approximately doubling the external light extraction efficiency. Such CDs/PVA composites also exhibit good photo-stability, and can be used as eco-friendly, low cost phosphors for solid-state lighting.
On the other hand, those CDs can also be utilized as eco-friendly luminophores for promising applications in luminescent solar concentrators (LSCs). Such LSCs can be used to concentrate the solar light to enhance the efficiency and reduce the material costs of solar cells. We have fabricated flexible LCSs based on hydrophobic CDs doped PDMS waveguide and characterize their performances using spectroscopic methods. We found that those hydrophobic CDs can be uniformly dispersed into PDMS waveguide and exhibit good photo-stability. The key metric of LSCs, namely, reabsorption losses, has also been investigated using excitation-position-dependent PL spectroscopy. Our demonstration can pave a way to further design efficient LSCs based on eco-friendly CDs in the future.

並列關鍵字

carbon dot ； light-emitting thin films ； luminescent solar concentrators

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