Radiation Laboratory and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
ACS Nano. 2012 Jun 26;6(6):5718-26. doi: 10.1021/nn301982e. Epub 2012 Jun 6.
Manipulation of energy and electron transfer processes in a light harvesting assembly is an important criterion to mimic natural photosynthesis. We have now succeeded in sequentially assembling CdSe quantum dot (QD) and squaraine dye (SQSH) on TiO(2) film and couple energy and electron transfer processes to generate photocurrent in a hybrid solar cell. When attached separately, both CdSe QDs and SQSH inject electrons into TiO(2) under visible-near-IR irradiation. However, CdSe QD if linked to TiO(2) with SQSH linker participates in an energy transfer process. The hybrid solar cells prepared with squaraine dye as a linker between CdSe QD and TiO(2) exhibited power conversion efficiency of 3.65% and good stability during illumination with global AM 1.5 solar condition. Transient absorption spectroscopy measurements provided further insight into the energy transfer between excited CdSe QD and SQSH (rate constant of 6.7 × 10(10) s(-1)) and interfacial electron transfer between excited SQSH and TiO(2) (rate constant of 1.2 × 10(11) s(-1)). The synergy of covalently linked semiconductor quantum dots and near-IR absorbing squaraine dye provides new opportunities to harvest photons from selective regions of the solar spectrum in an efficient manner.
操纵光能和电子转移过程在一个光收集组件是一个重要的标准来模拟自然光合作用。我们现在已经成功地按顺序组装 CdSe 量子点 (QD) 和 squaraine 染料 (SQSH) 在 TiO(2)薄膜和耦合能量和电子转移过程产生光电流在一个混合太阳能电池。当分别连接时,CdSe QD 和 SQSH 在可见光近红外辐照下向 TiO(2)注入电子。然而,如果 CdSe QD 通过 SQSH 链接器与 TiO(2)连接,则会参与能量转移过程。用 squaraine 染料作为 CdSe QD 和 TiO(2)之间的链接制备的混合太阳能电池表现出 3.65%的功率转换效率,并且在全球 AM 1.5 太阳条件下的光照下具有良好的稳定性。瞬态吸收光谱测量提供了进一步的深入了解之间的能量转移激发的 CdSe QD 和 SQSH(速率常数 6.7 × 10(10) s(-1))和界面电子转移激发的 SQSH 和 TiO(2)之间(速率常数 1.2 × 10(11) s(-1))。共价连接半导体量子点和近红外吸收 squaraine 染料的协同作用提供了新的机会,以有效地从太阳光谱的选择性区域收集光子。
Phys Chem Chem Phys. 2012-2-24