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(γ√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 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.