We quantify guest molecule aggregation and its effect on the photoconductive properties of guest-host thin films, depending on the guest concentration and host material. A high-performance anthradithiophene (ADT) derivative served as a guest, while functionalized benzothiophene (BTBTB) and polymethylmethacrylate (PMMA) were chosen as hosts. Aggregates exhibited redshifted optical absorption and photoluminescence (PL) spectra, as well as reduced PL quantum yields. Propensity toward guest aggregation differed for PMMA and BTBTB hosts. Photocurrents dramatically increased as the percentage of aggregated guest molecules increased due to considerably higher charge carrier mobility in the aggregates. At low guest concentrations, BTBTB films outperformed PMMA films.
|Journal||Applied Physics Letters|
|State||Published - Oct 18 2010|
Bibliographical noteFunding Information:
We thank M. Kendrick and G. Banton for technical assistance. This work was supported by NSF via CAREER program (Grant No. DMR-0748671).
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)