Engineering Semiconductor Layer Using Halonaphthalene Additives for Organic Opto-Inverter Circuits

Solution-processable organic field-effect transistors (OFETs) are at the forefront of the future of electronic circuits. They have the potential for low-cost, large-scale fabrication on a variety of substrates. However, their application in electronic circuits is challenged by the unforeseen presence of defects leading to lower mobility. In this contribution, the application of a photoactive polymer-based phototransistor in a digital electronic circuit is demonstrated. Initially, a solvent additive engineering strategy is adopted to tune the thin film morphology and reduce morphology-related defects, resulting in improved device performance. The incorporation of 1-bromonaphthalene improves mobility from 0.09 to 0.50 cm² V^–1 s^–1 with enhancement in both photoabsorption and photostability. The results are well supported by electrical characterization and photophysical and morphological studies. Thereafter, a unique architecture of an opto-inverter is presented using the OFET. In this work, an optoelectronic logic NOT gate is also fabricated by utilizing a simple resistive load circuit. This circuit is also demonstrated to perform the combined functionality of a logic gate and a transducer. Furthermore, this technique can be easily implemented for minimizing the circuit components and complexity by replacing a photodetector and a NOT gate with a single opto-inverter in applications requiring both.