Manifestation of carrier relaxation through the manifold of localized states in PCDTBT:PC60BM bulk heterojunction material: the role of PC84BM traps on the carrier transport

Wei Lin Leong; Gerardo Hernandez-Sosa; Sarah R Cowan; Daniel Moses; Alan J Heeger

doi:10.1002/adma.201104192

Manifestation of carrier relaxation through the manifold of localized states in PCDTBT:PC60BM bulk heterojunction material: the role of PC84BM traps on the carrier transport

Adv Mater. 2012 May 2;24(17):2273-7. doi: 10.1002/adma.201104192. Epub 2012 Mar 26.

Authors

Wei Lin Leong¹, Gerardo Hernandez-Sosa, Sarah R Cowan, Daniel Moses, Alan J Heeger

Affiliation

¹ Center for Polymers and Organic Solids, University of California, Santa Barbara, California 93106, USA.

PMID: 22451433
DOI: 10.1002/adma.201104192

Abstract

The transport and relaxation of photogenerated carriers in a bulk heterojunction (BHJ) material made of a blend of PCDTBT and PC(60) BM are studied as a function of the concentration of PC(84)BM impurities. For low concentrations of PC(84)BM, the increasing activation energy with delay time indicates transport dominated by trap-limited carrier drift while the photocarriers relax through a manifold of disorder-induced localized states near the band edge. In the BHJ material with high concentration of PC(84)BM, transport is dominated by carrier hopping within the PC(84)BM impurity band.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Fullerenes / chemistry*
Polymers / chemistry*
Quantum Theory
Solar Energy
Thiadiazoles / chemistry

Substances

Fullerenes
Polymers
Thiadiazoles
benzo-1,2,3-thiadiazole