Measurement of electron/hole mobility in organic/polymeric thin films using modified time-of-flight apparatus

We report, using modified time-of-flight (TOF) apparatus, the measurement of the drift mobility of electrons/holes in thin films of vapordeposited tris(8-hydroxyquinolinolato)aluminum (Alq3) and spin-cast poly(N-vinylcarbazole) (PVK) based on silicon. Drift mobilities of both carriers are strongly electric field and temperature dependent. At room temperature and an electric field of 2 × 105 V cm−1, the effective mobilities of electron and hole are 1 × 10−5 and 7.14 × 10−6 cm2 V−1 s−1, respectively, in a 200 nm thick samples corresponding to the two materials.