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, μ=μ0 exp(γE⎯⎯⎯√), 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 μ0=5.6×10−11 m2/V s and γ=5.0×10−4 (m/V)1/2 for holes. For electrons μ0=1.0×10−12 m2/V s and γ=8.0×10−4 (m/V)1/2 are obtained