Fluorene-based alternating and statistical copolymers were synthesized by employing reaction methods of Wittig

Heck and Suzuki. The copolymers were classified into three groups with the photoluminescence (PL) emission maxima at420

475 and 500 nm

respectively. Statistical copolymers with two chromophores having PL emission maxima at 420 and475 nm emitted light with the emission maximum at 475 nm on photoexcitation at 365 nm and improved the quantumefficiency by the energy transfer. However

the intramolecular energy transfer was inefficient compared to the intermolecular energy transfer when the two chromophores were apart from each other in the range of the Forster critical distance.Fluorene-pyridinedivinylene alternating copolymer was synthesized by the Wittig reaction and found to have physical

electronic and electrochemical properties of the individual units intact.The double-layered light emitting diode(LED) with the statistical copolymer as an emitting layer and the pyridine-containing copolymer as an electron transporting-hole blocking layer

which were sandwiched between ITO and Al

displayed a quantum efficiency of 0.1%.