Accession Number:

AD1071023

Title:

Asymmetric Electron Transfer Rates at Organic-Inorganic Hybrid Interfaces Via Self-Assembled Bilayers

Descriptive Note:

Technical Report,30 Sep 2014,29 Mar 2018

Corporate Author:

Florida State University Tallahassee United States

Personal Author(s):

Report Date:

2018-03-29

Pagination or Media Count:

15.0

Abstract:

Major Goals The goal of this research is to influence electron transfer dynamics at an organic-inorganic interface in order to maximize the rate of electron transfer in one direction forward electron transfer, FET and suppress it in the reverse direction back electron transfer, BET. As outlined in the original proposal these goals are to be achieved by 1 tuning the energy of the bridge so that FET and BET occur through two different mechanisms, fast incoherent hopping and slower coherent tunneling, respectively, and 2 to generate self-assembled bilayers containing asymmetric bridges that asymmetrically influence electron transfer rates between the active material and the metal oxide surface.Accomplishments The Hanson research group has introduced self-assembled bilayers as a simple, scalable, modular, and effective method for manipulating electron transfer at organic-inorganic interfaces. Our initial efforts involved altering the length of a photophysically and electrochemically inert bridging molecule Figure 1a.J. Phys. Chem. C 2015, 119, 3502 The length of the molecular bridge i.e. distance between the dye and the semiconductor did exponentially decrease FET decreased Jsc and BET slowed recombination and increased Voc, Figure 1b indicating that the bridge and metal ion are acting as a tunneling barrier for electron transfer events.ACS Appl. Mater. Interfaces 2015, 7, 27730 Unfortunately, the observed enhances in Voc and FF are far outweighed by the significant decrease in Jsc and thus overall device performance decreases with increasing bridge length. Following our proof-of-concept distance dependence studies we then shifted our focus to tuning the energy of the bridging molecule and metal ion. We demonstrated that CuII linking ions can have a profound effect on the excited-state dynamics in the bilayer film.Phys. Chem. Chem. Phys. 2017, 19, 2679

Subject Categories:

  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE