Program for Research in Conducting Polymers

Principal accomplishments during the past year related to Light Emitting Diodes fabricated from conducting polymers and to the related fundamental scientific and materials issues. Progress has been made toward passivating the low work function electron-injecting contact to the point where stable operation outside the dry box is routine. Transient electroluminescence from polymer LEDs has been reported RC limited response with rise and fall times below 50 nanoseconds has been achieved. The absence in saturation in pulsed operation implies that such devices can be used in applications which require multiplexing e.g. displays. Photoconductivity studies of the parent PPV material demonstrate that the absorption and emission arise directly from a Pi-Pi interband transition rather than a bond exciton. Work during the next year will focus on synthesis of blue emitters as well as a variety of fundamental experiments enabled by the passivation of the devices designed to clarify the mechanism and to enhance the efficiencies.