Development of Sol-Gel Synthesized ZnO Nanoparticle-Incorporated Polymer-Based X-Ray Detectors: A Comparative Investigation of Device Architectures

Abstract

The extensive use of X-rays in medical, security, and industrial applications has led to considerable interest in the development of advanced X-ray detection technologies. Conventional detectors based on inorganic semiconductors, such as silicon or germanium, face challenges, including high production costs and limited flexibility. This study investigates the potential of organic semiconductors, particularly ZnO nanoparticles (ZnO NPs) incorporated into a poly(3-hexylthiophene) (P3HT) matrix, for X-ray detection. The ZnO NPs, selected for their high mobility, large band gap, and thermal stability, were synthesized via a sol-gel method and integrated into P3HT to form composite layers at varying ratios (1:0.25, 1:0.5, and 1:0.75). Two different device architectures were fabricated: interdigitated (IDT) electrodes as resistive-based and diode-based devices with ITO/ZnO/P3HT/Graphite configurations. The influence of the ZnO NP concentration and device structure on X-ray detection performance was systematically investigated and evaluated. The results indicated that increasing the ZnO NP content enhanced electron transportation and improved the X-ray sensitivity of the devices. The ITO/ZnO/P3HT/Graphite device with a P3HT ratio of 1:0.75 exhibited the highest sensitivity (0.94 μGy/s) and the fastest response times, outperforming those of the IDT-based devices. This study demonstrates that organic semiconductors doped with ZnO NPs are promising candidates for cost-effective, flexible, and high-performance X-ray detectors. © 2025 Elsevier B.V., All rights reserved.