Polymer light-emitting diodes (PLEDs) offer potential advantages for application in displays and lightings over other competing technologies due to their cheap and easy solution-based fabrication processing

e.g.

spin coating

screen printing or inkjet printing

which allows for the possibility of low-cost and large-(area) mass production. Among polymer based systems

the fluorescent/phosphorescent dye doped polymer systems have the unique advantage of simplicity and flexibility. One of methods to achieve highly efficient

full color information display is polymers doped with highly efficient fluorescent dyes

which requires a energy match but also an efficient energy transfer between polymer (host) and dye (guest). DCM is a highly fluorescent orange-red laser dye and widely used in PLEDs as guest

and poly-vinylcarbazole (PVK) is generally used as a host material for PLEDs due to its high energy singlet or/and triplet excited states for fluorescent or/and phosphorescent dopants

favorable film-forming properties

durability

and hole mobility. Highly efficient PLEDs with DCM doped into PVK

as a light-emitting layer

have been demonstrated due to singlet formed in the host material (PVK) which can efficiently transfer energy to the guest (DCM) via Frster/singlet transfer processes. Recently

more attention has also been paid on the detail mechanism

e.g. energy transfer and charge trapping processes in PLEDs. Photoluminescence and energy transfer in DCM doped PVK thin films were investigated by steady-state and time-resolved ultra-fast photoluminescence. We observed that the DCM emission intensity increased and the PVK fluorescent lifetime reduced with increasing DCM doping concentration due to efficient Frster/singlet energy transfer from PVK to DCM

which is strongly correlated with a large spectral (overlap) between DCM absorption and PVK emission. The observed results were comparable with the (calculations) based on Frster energy transfer theory and the fluorescent decay data were estimated according to exponential function.