Tailor-made control of fluorescence in an array of polymer nanosheets for optical memory application

In this study, we describe tailor-made control of fluorescence imensity in an array of polymer nanosheets assemblies by combining energy trasnfer with electron transfer process. The assemblies were made of thre-type polymer FLangmuir-Blodgett films. The first layer contains phenanthrene chromophore, the second layer contains anthracene chromophore, and then the third layer having dinitrobenzne unit is assembled. The phenanthrene (Phen) layers play a role of energy donor of the anthracene (An) layers under light excitation (λ_ex = 298 nm), and the dinitrobenzene layer quenches the exited state of anthracene by electron transfer reaction. As the result, weak fluorescence was observed from the nanosheet. However, when the photocycloaddition of the anthracene molecules proceeds by 368 nm irradition the efficiency of energy transfer from phenanthrene to anthracene decrease. As a result the phenanthrene fluorescence was recovered. The phenanthrene emission can be controlled in a tailor manner by 368 nm irradition. This tailor-made control can be applied to luminescence-based optical memory.