Enforced one-dimensional photoconductivity in core-cladding hexabenzocoronenes.
Photoconductivity in contorted hexabenzocoronene liquid crystals is found to be exclusively one-dimensional. Spectroscopic measurements and density functional theory support the existence of two pi-systems attributed to a low-energy radialene-core and higher energy out-of-plane alkoxyphenyl rings. Persistent photocurrents, measured as a function of field, channel length, and intensity, fit a stretched exponential characteristic of intracolumnar transport, restricted through the radialene-core by the alkoxyphenyl-cladding. Bimolecular recombination is enhanced with increasing carrier concentration by the system's one-dimensionality.
Cohen
Yaron S
YS
Department of Chemistry, Columbia University, New York, New York 10027, USA.
Xiao
Shengxiong
S
Steigerwald
Michael L
ML
Nuckolls
Colin
C
Kagan
Cherie R
CR