Simultaneous measurement of electron and hole mobilities in polymer light-emitting diodes

The transport properties of electrons and holes in a poly(p-phenylene vinylene)-based polymer light-emitting diode (PLED) have been investigated. Using admittance spectroscopy, we are able to simultaneously obtain the electron and hole mobility, mu=mu(0) exp(gamma root E), in a single PLED. The dynamics of the electron and hole transport are separated in the frequency domain as a result of the different transit times. At room temperature, we find mu(0)=5.6x10(-11) m(2)/V s and gamma=5.0x10(-4) (m/V)(1/2) for holes. For electrons mu(0)=1.0x10(-12) m(2)/V s and gamma=8.0x10(-4) (m/V)(1/2) are obtained. (C) 2000 American Institute of Physics. [S0003-6951(00)03538-5].