Tuning the threshold voltage by inserting a thin molybdenum oxide layer into organic field-effect transistors

The authors report on the organic field-effect transistors based on copper phthalocyanine with a inserted layer of molybdenum oxide (Mo O3). After applying a positive gate voltage of 100 V, the threshold voltage had a large shift from -11.8 to +66.2 V and the device operating model was changed from the enhancement model into the depletion one. A possible mechanism is believed to be originated from the stored charges in the interface between the thin Mo O3 layer and the active layer. Largely reversible shift in the threshold voltage and retention time were also obtained in the devices by the programs used.