Molecular Engineering of Dye-doped Polymers for Optoelectronics† Alexander Ishchenko* Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5, Murmanskaya St., Kiev-94, 02094, Ukraine ABSTRACT WWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWW The main approaches to molecular engineering of pros- pective dye-doped polymer matrices for optoelectronics have been considered. The advantages of such matrices over polymers and dyes separately were analyzed. It was shown that these advantages can be realized in the case where a doping of polymers by low-molecular-weight dyed impurities does not essentially distort spectral, luminescent and nonlinear optical properties of the individual components of polymer composition. The influence of polymer nature and chemical constitution of organic dyes on photophysical and photochemical properties of these matrices was analyzed. Processes of dye aggregation in polymers were characterized. Their influence on photophysical properties and the photo- chemical stability of dye-doped materials was discussed. The different approaches for struggle with it is offered. The influence of the method of introduction of a dye into a polymer on the output parameters of dyed materials was considered. The main paths of energy degradation of electronic excitation in such materials ± internal conversion, electron transfer and photoisomerization ± were analyzed. The role of dyes in the process of generation, in recombination and in the carriage of charges in photoconductive polymers was discussed. The prospects for the application of dye-doped polymer materials as passive Q-switches of solid-state lasers, as active laser media with large Stokes shift, as luminescent solar converters and as electroluminescent emitters were demonstrated. Copyright  2003 John Wiley & Sons, Ltd. KEYWORDS: conjugated polymers; dyes; lumines- cence; polyurethanes; photophysics INTRODUCTION WWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWW Polymers for optoelectronics can be divided into two large groups: photoconducting and non- photoconducting polymers. Photoconducting poly- mers are effective converters of electric and light energy owing to the interaction between electro- magnetic radiation and p-electrons of polymer conjugated bonds [1]. However a change range of spectral, luminescent and non-linear optical prop- erties is less than analogues range or organic dyes. Therefore it is necessary to create dye-doped polymer matrices. Dye-doped polymers are prospective materials for optoelectronics, especially for devices for use in quantum electronics [2], electroluminescence [3], photovoltaic solar cells [4], and recording and storage of the information [5]. They enable the transformation of light radiation over a wide spectral range with higher efficiency, than poly- mers and dyes separately. However, these advan- tages can be realized only in the case where a doping of polymers by low-molecular-weight dyed impurities does not essentially distort the spectral, luminescent and nonlinear optical properties of Received 12 January 2002 Revised 1 April 2002 Accepted 11 April 2002 POLYMERS FOR ADVANCED TECHNOLOGIES Polym. Adv. Technol. 13, 744±752 (2002) Published online in Wiley InterScience (www.interscience.wiley.com). DOI:10.1002/pat.269 *Correspondence to: A. Ishchenko, Institute of Organic Chem- istry, National Academy of Sciences of Ukraine, 5, Murmans- kaya St., Kiev-94, 02094, Ukraine. E-mail: alexish@i.com.ua † This paper was presented at PAT 2001±Eilat, Israel Copyright  2003 John Wiley & Sons, Ltd.