Institute of Nanotechnology and Advanced Materials, Bar Ilan University, Ramat-Gan 52900, Israel.
ACS Nano. 2010 Mar 23;4(3):1293-8. doi: 10.1021/nn100021b.
A new design of dye-sensitized solar cells involves colloidal semiconductor quantum dots that serve as antennas, funneling absorbed light to the charge separating dye molecules via nonradiative energy transfer. The colloidal quantum dot donors are incorporated into the solid titania electrode resulting in high energy transfer efficiency and significant improvement of the cell stability. This design practically separates the processes of light absorption and charge carrier injection, enabling us to optimize each of these separately. Incident photon-to-current efficiency measurements show a full coverage of the visible spectrum despite the use of a red absorbing dye, limited only by the efficiency of charge injection from the dye to the titania electrode. Time resolved luminescence measurements clearly relate this to Forster resonance energy transfer from the quantum dots to the dye. The presented design introduces new degrees of freedom in the utilization of quantum dot sensitizers for photovoltaic cells. In particular, it opens the way toward the utilization of new materials whose band offsets do not allow direct charge injection.
一种新型染料敏化太阳能电池的设计涉及胶体半导体量子点，它们作为天线，通过非辐射能量转移将吸收的光引导到电荷分离染料分子。胶体量子点供体被掺入固体二氧化钛电极中，导致高能量转移效率和显著提高电池稳定性。这种设计实际上将光吸收和载流子注入过程分开，使我们能够分别对它们进行优化。尽管使用了红色吸收染料，但入射光子-电流效率测量显示可见光光谱的完全覆盖，仅受染料向二氧化钛电极注入电荷的效率限制。时间分辨荧光测量清楚地将其与量子点到染料的福斯特共振能量转移相关联。所提出的设计为量子点敏化剂在光伏电池中的应用引入了新的自由度。特别是，它为利用新材料开辟了道路，这些新材料的能带偏移不允许直接电荷注入。
