title: Charge transport in a liquid crystalline triphenylene polymer monolayer at air-solid interface.
abstract: We have prepared a monolayer of a novel liquid crystalline polymer derived from 2,6-dihydroxy-3,7,10,11-tetraalkoxy-triphenylene (PHAT) at an air-water interface and transferred it onto freshly cleaved mica as well as gold coated mica substrates by the Langmuir-Blodgett (L-B) technique. The atomic force microscope (AFM) images of these L-B films show a uniform coverage with a thickness of 1.5 nm. Electrical conductivity measurements were carried out on the PHAT monolayer deposited on the gold coated mica substrate using a current sensing AFM (CSAFM). The gold substrate-PHAT monolayer-cantilever tip of CSAFM forms a metal-insulator-metal (M-I-M) junction. The CSAFM yields a non-linear current-voltage (I-V) curve for the M-I-M junction. The analysis of the I-V characteristics of the M-I-M junction indicated that the charge transport in the liquid crystalline polymer monolayer is by the direct tunneling mechanism. The barrier height for the PHAT monolayer was estimated to be 1.22 ± 0.02 eV.
authors.affiliation: Centre for Nano and Soft Matter Sciences, P. B. No: 1329, Jalahalli, Bangalore - 560 013, India. suresh@cens.res.in.
authors.forename: H N
authors.initials: HN
authors.lastname: Gayathri
authors.affiliation: School of Physical Sciences, Central University of Karnataka, Kadaganchi - 585367, Karnataka, India.
authors.forename: Bharat
authors.initials: B
authors.lastname: Kumar
authors.affiliation: Centre for Nano and Soft Matter Sciences, P. B. No: 1329, Jalahalli, Bangalore - 560 013, India. suresh@cens.res.in.
authors.forename: K A
authors.initials: KA
authors.lastname: Suresh
authors.affiliation: Raman Research Institute, Sadashivanagar, Bangalore - 560080, India.
authors.forename: H K
authors.initials: HK
authors.lastname: Bisoyi
authors.affiliation: Raman Research Institute, Sadashivanagar, Bangalore - 560080, India.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Kumar