Heavy-to-light electron transition enabling real-time spectra detection of charged particles by a biocompatible semiconductor

The lack of biocompatible and high-performance detector materials hinders the development of wearable/implantable personal dosimeters. This paper introduces a solution-grown biocompatible organic single crystalline semiconductor (OSCS), 4-Hydroxyphenylacetic acid (4HPA), enabling real-time spectral detection of charged particles with single-particle sensitivity. 4HPA exhibits a large electron drift velocity (5 × 10⁵ cm s⁻¹) and high resistivity ((1.28 ± 0.003) × 10¹² Ω cm) due to π-π overlaps and a high-energy L1 level. 4HPA detectors achieve record spectral detection of charged particles with 36% energy resolution, (μτ)e of (4.91 ± 0.07) × 10⁻⁵ cm² V⁻¹, and a detection time of 3 ms. High X-ray detection sensitivity (16,612 µC Gy⁻¹air cm⁻³) and long-term stability are also demonstrated.

Dou Zhao, Ruiling Gao, Wei Cheng, Mengyao Wen, Xinlei Zhang, Tomoyuki Yokota, Paul Sellin, Shengyuan A. Yang, Li Shang, Chongjian Zhou, Takao Someya, Wangji Jie, Yadong Xu