Atomic-Scale Perspective of Ultrafast Charge Transfer at a Dye-Semiconductor Interface

作者：Siefermann Katrin R; Pemmaraju Chaitanya D; Neppl Stefan; Shavorskiy Andrey; Cordones Amy A; Vura Weis Josh; Slaughter Daniel S; Sturm Felix P; Weise Fabian; Bluhm Hendrik; Strader Matthew L; Cho Hana; Lin Ming Fu; Bacellar Camila; Khurmi Champak; Guo Jinghua; Coslovich Giacomo; Robinson Joseph S; Kaindl Robert A; Schoenlein Robert W; Belkacem Ali; Neumark Daniel M; Leone Stephen R; Nordlund Dennis; Ogasawara Hirohito; Krupin Oleg; Turner Joshua J

来源：Journal of Physical Chemistry Letters, 2014, 5(15): 2753-2759.

DOI：10.1021/jz501264x

Understanding interfacial charge-transfer processes on the atomic level is crucial to support the rational design of energy-challenge relevant systems such as solar cells, batteries, and photocatalysts. A femtosecond time-resolved core-level photoelectron spectroscopy study is performed that probes the electronic structure of the interface between ruthenium-based N3 dye molecules and ZnO nanocrystals within the first picosecond after photoexcitation and from the unique perspective of the Ru reporter atom at the center of the dye. A transient chemical shift of the Ru 3d inner-shell photolines by (2.3 +/- 0.2) eV to higher binding energies is observed 500 fs after photoexcitation of the dye. The experimental results are interpreted with the aid of ab initio calculations using constrained density functional theory. Strong indications for the formation of an interfacial charge-transfer state are presented, providing direct insight into a transient electronic configuration that may limit the efficiency of photoinduced free charge-carrier generation.

• 出版日期2014-8-7