Polymer solution light-emitting devices

Traditional conjugated polymer electroluminescent devices are thin-film solid-state devices consisting of a thin polymer film sandwiched between two electrodes. In this letter, we demonstrate the generation of luminescence from polymer solutions in a compact polymer solution configuration. This unique polymer solution light-emitting device (SLED) consists of a thin layer of a polymer solution sandwiched between two transparent indium-tin-oxide/glass substrates. When biased, the device turns on at slightly above the band-gap energy and emits bright luminescence. The emission spectrum is consistent with the photoluminescence spectrum obtained from the polymer solution. We suggest that the mechanism of the SLED is due to the electrogenerated chemiluminescence effect. The SLED combines the advantages of low operating voltage, and easy and low-cost fabrication. The SLED is also a highly transparent emissive device when transparent materials are used for the electrodes and the substrates. (C) 1999 American Institute of Physics. [S0003-6951(99)02414-6].