Complementary circuits of ambipolar organic/oxide thin-film transistors for AMFPD applications

Air-stable ambipolar thin-film transistors (TFTs) based on double active layer of pentacene / a-IGZO (amorphous In₂O₃-Ga ₂O₃-ZnO) have been fabricated on SiO₂ /p-Si substrates. The a-IGZO exhibits n-channel behavior, while pentacene presents p-channel characteristics. Most n-type organic materials are easily affected by moisture and oxygen, thus the measurement of ambipolar devices in ambience air is difficult. However, a-IGZO not only has outstanding mobility but also has good stability while being measured in ambient air. In our work, a CMOS-like inverter was constructed by using two identical ambipolar transistors and the voltage gain up to 70 was obtained. The inverter can be operated in both the first and the third quadrants implies simplified circuit design for AMFPD applications.