| Summary: | 博士 === 國立成功大學 === 微電子工程研究所碩博士班 === 98 === The current?voltage characteristics of the gate?controlled three?terminal organic?based transistors with memory effect and negative differential resistances (NDR) were studied. Gold and 9,10-di(2-naphthyl)anthracene (ADN) were used as the metal electrode and active channel layer of the transistors, respectively. By using various gate?source voltages, the memory and NDR characteristics of the transistors can be modulated. The memory and NDR characteristics of the transistors were attributed to the formation of trapping sites in the interface between Au electrode and ADN active layer caused by the defects, when Au metal deposited on the ADN active layer. However, the different in the current values for the ON and OFF states can be improved. The vertical structure was used to improve the memory characteristics of the transistors.
Three?terminal vertical organic memory transistors were fabricated to investigate the memory mechanisms and the relation between memory behavior and applied electrical field. The 9,10-di(2-naphthyl)anthracene (ADN) was used as the active channel layer for the organic memory transistors. In both the ON and OFF state of the organic memory transistors, the drain?source currents (IDS) were modulated by applying various gate?source voltages (VGS). The switching drain?source voltage (VDS) decreased with an increase in applied VGS voltages. The ON/OFF IDS current ratio of the organic memory transistors could be modulated up to the maximum value of 2.02x105 by applying VGS voltage bias.
To investigate the memory bistable mechanisms of organic memory devices, the structure of [top Au anode/9,10-di(2-naphthyl)anthracene (ADN) active layer/bottom Au cathode] was deposited using a thermal deposition system. The Au atoms migrated into the ADN active layer was observed from the secondary ion mass spectrometry. The density of 9.6×1016 cm-3 and energy level of 0.553 eV of the induced trapping centers caused by the migrated Au atoms in the ADN active layer were calculated. The the memory bistable behaviors of the organic memory devices were attributed to the induced trapping centers. The energy diagram was established to verify the mechanisms.
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