Photoelectrochemical properties of Langmuir–Blodgett films of two squaraine derivatives

Abstract

Photocurrent generation from LangmuirÈBlodgett (LB) overlays on indium tin oxide (ITO) electrodes, where the active components are 2,4-bis[4-(dibutylamino)-2-hydroxyphenyl]squaraine (1) and the unsubstituted analogue, 2,4-bis[4-(dibutylamino)phenyl]squaraine (2), have been investigated. Dye 1 shows improved behaviour compared with the latter and di †erences in performance are attributed to a modiÐed aggregate structure, this being indicated by variations in the LB Ðlm spectra. The photocurrent generation is enhanced by the presence of electron acceptors, e.g. N,N@-dimethyl-4,4@-bipyridinium diiodide (MV2`), but quenched by electron donors, e.g. hydroquinone (HQ). The concentration dependence is reported.

Structure and physical properties of isopropyl TTF semisquarates

“…squaraine dyes, also show remarkable optical properties such as non-linear optics 37,38 and photoelectricity. 39 Here we report the synthesis, characterization and physical properties of isopropyl TTF semisquarates. Although the hydroxyl groups of these molecules are still protected by an isopropyl group, these molecules show remarkable physical properties such as solvatochromism and electrical conductivity in their neutral solid form.…”