562015-03-24 , 法政大学大学院理工学・工学研究科
The carrier mobility of the pentacene organic transistors is low and there is a problem in air stability.In the present study, the pentacene thin film was fabricated on a Si substrate (1 cm × 1 cm) by thermal evaporation. The degradation of pentacene film on Si substrate by air exposure of relative humidity (≊70 %) is investigated by means of Raman spectroscopy, Furrier transformation infrared spectrometry (FTIR), Atomic force microscopy (AFM) X-ray Photoelectron Spectroscopy (XPS), Elastic Recoil Detection Analysis (ERDA) and Van der Pauw method.In raman spectrum as-deposited pentacene film after air exposure shows that the peak of 1170 cm-1 decreased by oxidation of pentacene film. XPS measurement indicates the increase in the O-1s peak for longer exposure time. In addition, the change in the surface morphology caused by adsorption of water of a pentacene film from ERDA and AFM image was confirmed. Increase of a specific resistance by exposure to the atmosphere wasn't observed in ratio resistance measurement, but decrease of the mobility in the pentacene device is often reported.