Photoelectric conversion and fluorescence quenching in mixed-dye monolayers: inhomogeneous distribution of dyes

✍ Scribed by Yasushi Nishiyama; Terukazu Azuma; Naohiro Obata; Kazuo Kasatani; Hiroyasu Sato

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 980 KB
• Volume: 59
• Category: Article
• ISSN: 1010-6030
• DOI: 10.1016/1010-6030(91)87086-b

✦ Synopsis

Photoelectric conversion and fluorescence quenching were studied using Langmuir-Blodgett (LB) monolayers incorporating two dyes: 2,8-bis(dimethylamino)dodecylacridinium bromide (BDA) and 3,3'-dioctadecylthiacarbocyanine iodide (DTC). When the LB monolayer was formed on a semiconductor electrode, electron injection into the electrode occurred from both dyes, in the presence of concomitant two-dimensional energy transfer (ET). The ET led to a decrease in photocurrent. In the fluorescence measurements, the fluorescence of the donor was quenched by the two-dimensional ET to the acceptor. The efficiency of ET was calculated from the decrease in the photocurrent and from the fluorescence quenching, and was compared with that predicted by the theory of two-dimensional ET with the assumption of a homogeneous distribution of the two dyes. The effect of DTC was much smaller than expected, indicating an inhomogeneous distribution of the dyes. Microscopic fluorescence measurements gave an indication of the inhomogeneous distribution of the dyes.