Li Yi, Chen Hu, Hao Zhao, Wang Zixuan, Wu Xingyang, Lu Xiuzhen, Li Xifeng, Zhang Jianhua
School of Microelectronics, Shanghai University, Shanghai 200444, China.
Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Shanghai 200072, China.
ACS Appl Mater Interfaces. 2024 Feb 28;16(8):10417-10426. doi: 10.1021/acsami.3c18529. Epub 2024 Feb 20.
Organic semiconducting materials are promising for the fabrication of flexible ionizing radiation detectors for imaging because of their tissue equivalence, simple large-scale processing, and mass production. However, it is challenging to achieve high-sensitivity detection for organic direct detectors prepared by low-cost solution processing because of the compromise between thickness and carrier transport. In this study, high-performance organic direct X-ray detectors were fabricated by building a micrometer-thick bulk heterojunction (BHJ) using poly(3-hexylthiophene-2,5-diyl) (P3HT):(6,6)-phenyl c71 butyric acid methyl ester. A 5 μm BHJ film was fabricated by drop-casting and enhanced crystallization of P3HT using binary solvents and high-boiling-point additives to improve the charge carrier mobility. Furthermore, this organic direct X-ray detector has a sensitivity of >654.26 μC Gy s and a self-powered response. Because of the architecture of the thick active layer and the energy cascade in this diode detector, it has a very low dark current of 46.26 pA at -2 V. A fast and efficient approach was developed for fabricating thick, highly mobile organic BHJ films for high-performance direct X-ray detectors. It has great potential for application in a new generation of flexible and portable large-area flat-panel detectors.
有机半导体材料因其组织等效性、简单的大规模加工和批量生产，在制造用于成像的柔性电离辐射探测器方面很有前景。然而，由于厚度与载流子传输之间的权衡，对于通过低成本溶液加工制备的有机直接探测器而言，实现高灵敏度检测具有挑战性。在本研究中，通过使用聚（3-己基噻吩-2,5-二亚基）（P3HT）：（6,6）-苯基C71丁酸甲酯构建微米厚的体异质结（BHJ），制备了高性能有机直接X射线探测器。通过滴铸法制备了5μm的BHJ薄膜，并使用二元溶剂和高沸点添加剂增强P3HT的结晶，以提高电荷载流子迁移率。此外，这种有机直接X射线探测器的灵敏度大于654.26μC Gy s ，且具有自供电响应。由于该二极管探测器中厚有源层的结构和能量级联，其在-2V时的暗电流非常低，为46.26pA。开发了一种快速有效的方法来制备用于高性能直接X射线探测器的厚的、高迁移率的有机BHJ薄膜。它在新一代柔性便携式大面积平板探测器中具有巨大的应用潜力。
