Performance Enhancement of Organic Ternary Logic Circuits through UV Irradiation and Geometry Optimization

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AbstractMultivalued logic (MVL) circuits offer higher information density compared with conventional binary logic circuits. However, achieving a proper balance between logic states and a low‐voltage gain remains a challenge in MVL devices. This study proposes two strategies to address this problem: using the optical absorption of organic semiconductors and optimizing device geometry. A ternary inverter is fabricated using a series circuit consisting of an antiambipolar transistor with a heterojunction of C8‐BTBT and PTCDI‐C8 semiconductors and a PTCDI‐C8 transistor. Although the inverter exhibits three distinct logic levels, it suffers from an inadequate voltage balance between the ternary logic states. To overcome this, UV light irradiation is employed first to modulate the transistor characteristics, thus improving the output voltage level and input voltage range of the logic ½ state. Subsequently, the channel length of the PTCDI‐C8 transistor is optimized to further enhance the voltage transfer characteristics of the inverter. Through these combined techniques, ideal output voltage levels are achieved for all three logic states along with an enhanced voltage gain during the transition from the logic ½ state to the logic 0 state. This work is thus an advancement toward reliable, efficient organic ternary logic circuits.