Monday, 07 July, 2014
Terahertz spectroscopy on hole transport in pentacene thin film
S. Engelbrecht, M. Prinz, T. Arend, and R. Kersting -
Appl. Phys. Lett., Vol. 105 (1), 012101 (2014)
Charge transport in pentacene thin films is investigated using terahertz electromodulation spectroscopy. Although the material is highly polycrystalline, a hole mobility of about 20 cm2/Vs is found, which exceeds the mobility obtained in DC measurements by orders of magnitude. The high AC mobility results from a motion of charge carriers, which is not hindered by grain boundaries. An upper limit of mh∗ ≈ 0.8 me is deduced for the conductivity effective mass of holes in pentacene.