Heavy-to-light electron transition enabling real-time spectra detection of charged particles by a biocompatible semiconductor
Dou Zhao, Ruiling Gao, Wei Cheng, Mengyao Wen, Xinlei Zhang, Tomoyuki Yokota, P.J. Sellin, Shengyuan A. Yang, Li Shang, Chongjian Zhou, Takao Someya, Wanqi Jie, Yadong Xu
Abstract
Abstract The current challenge of wearable/implantable personal dosimeters for medical diagnosis and radiotherapy applications is lack of suitable detector materials possessing both excellent detection performance and biocompatibility. Here, we report a solution-grown biocompatible organic single crystalline semiconductor (OSCS), 4-Hydroxyphenylacetic acid (4HPA), achieving real-time spectral detection of charged particles with single-particle sensitivity. Along in-plane direction, two-dimensional anisotropic 4HPA exhibits a large electron drift velocity of 5 × 10 5 cm s −1 at “radiation-mode” while maintaining a high resistivity of (1.28 ± 0.003) × 10 12 Ω·cm at “dark-mode” due to influence of dense π-π overlaps and high-energy L1 level. Therefore, 4HPA detectors exhibit the record spectra detection of charged particles among their organic counterparts, with energy resolution of 36%, ( μt ) e of (4.91 ± 0.07) × 10 −5 cm 2 V −1 , and detection time down to 3 ms. These detectors also show high X-ray detection sensitivity of 16,612 μC Gy abs −1 cm −3 , detection of limit of 20 nGy air s −1 , and long-term stability after 690 Gy air irradiation.