The Polymer Society of Korea

Abstract

In this study, novel conjugated polymers containing electron-withdrawing building blocks, easily synthesized from a 2-aminothiazole-4-carboxylate schiff base commonly used as a pharmaceutical intermediate, are developed for high-performance organic photodetectors (OPDs) and fingerprint-on-display (FoD) sensors. Through alkyl chain engineering of the synthesized polymers, the OPDs achieved the highest photocurrent density and lowest dark current density, resulting in device performance with a promising responsivity of 0.42 A/W and a specific detectivity of 2.6 × 10¹³ Jones at −2 V under 810 nm near-infrared irradiation. In addition, they exhibited excellent performance with a rising response time of 3–4 µs, falling response time of 6–11 µs, and −3 dB cut-off frequency of 80–100 kHz. Finally, the OPD is integrated into an organic thin-film transistor (OTFT) array to build a FoD sensor with 80 × 80 µm² pixels, resulting in the successful acquisition of a digital fingerprint image.