The Polymer Society of Korea

Abstract

The development of portable X-ray detectors is necessary for diagnosing fractures in unconscious patients in emergency situations. However, this is quite challenging because of the heavy weight of the scintillator and silicon photodetectors. This study presents a novel biTPD-based polymer donor (PBDT-biTPD) that exhibits excellent photodetection properties even in a thick photoactive layer, owing to the symmetric backbone and highly soluble molecular structure of biTPD. The ability of PBDT-biTPD to strongly suppress the dark current density (~10^–10 A/cm²) at a negative bias (–2.0 V) while maintaining high responsivity (0.29 A/W) even at a thickness of 700 nm results in a maximum shot-noise-limited specific detectivity of D_sh*=2.18×10¹³ Jones in the OPDs. Printed OPDs are developed by slot-die coating for use in X-ray detectors, which exhibit D_sh* = 2.73×10¹² Jones with clear rising (0.26 s) and falling (0.29 s) response times upon X-ray irradiation.