Advanced Technology Institute, University of Surrey, Guildford, Surrey GU2 7XH, UK.
Phys Chem Chem Phys. 2010 Jul 21;12(27):7371-7. doi: 10.1039/c003179h. Epub 2010 May 13.
Charge transfer interactions between PbS nanocrystals (NCs) and tetrathiafulvalene (TTF) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) are studied using optical spectroscopy. Selective quenching of PbS NC photoluminescence (PL) by TTF is observed and related to the relative alignment of the highest occupied molecular orbital (HOMO) of TTF and the PbS NC 1s(h) energy level. TCNQ is also found to quench PbS NC PL irrespective of the NC bandgap. A ground-state charge transfer mechanism between PbS and TCNQ is proposed to account for the observed quenching indirectly supported by observed changes in the absorption spectra of PbS-TTF and PbS-TCNQ solutions. Additionally, a second emission band in the visible spectral region ( approximately 675 nm) is found upon excitation of PbS-TCNQ solutions. These results are of interest for the future design of charge-transfer systems for use in hybrid organic-inorganic systems.
采用光学光谱法研究了 PbS 纳米晶体（NCs）与四硫富瓦烯（TTF）和 7,7,8,8-四氰基对醌二甲烷（TCNQ）之间的电荷转移相互作用。观察到 TTF 选择性猝灭 PbS NC 光致发光（PL），并与 TTF 的最高占据分子轨道（HOMO）和 PbS NC 1s（h）能级的相对排列有关。还发现 TCNQ 无论 NC 带隙如何都能猝灭 PbS NC PL。提出了 PbS 和 TCNQ 之间的基态电荷转移机制，间接证实了观察到的吸收光谱变化，解释了观察到的猝灭现象。此外，在激发 PbS-TCNQ 溶液时，在可见光谱区域（约 675nm）发现了第二个发射带。这些结果对于未来设计用于混合有机-无机系统的电荷转移系统具有重要意义。
