Effects of O2 and H2O on electrical characteristics of pentacene thin film transistors

Abstract The effects of O 2 and H 2 O on the electrical characteristics of pentacene thin film transistors have been investigated using in situ and ex situ I – V measurements. We found that O 2 enhances the saturation current by about 10%, and the mobility is only slightly increased. The effect of H 2 O on the device performance is considerably complicated. The physically absorbed water degrades the device performance, and the chemically absorbed water interacts with pentacene to form pentacene/(H 2 O) n clusters, which enhance the saturation current. On the other hand, the effect of H 2 O is found to be partly reversible after repumping to vacuum due to the undissociated clusters, which attribute to the variations of the saturation current and field effect mobility.