Lone‐pair Electrons Enhancement Effect: SnTe₃O₈ Hard X‐ray Detection with Stable High‐temperature Sensitivity and Ultralow Detection Limit

Abstract Sensitivity and detection limit of X‐ray detectors are crucial for security checks, medical diagnoses, and industrial inspections. In this study, it is reported that introducing some cations containing lone‐pair electrons is beneficial for enhancing the Compton scattering effect and thus improving X‐ray detection performance. As an example, SnTe₃O₈ is selected and grown as a novel high‐temperature X‐ray detection crystal. Because of the high resistivity of 2 × 10¹⁴ Ω cm and high mobility lifetime product of 3.22 × 10⁻⁴ cm² V⁻¹, SnTe₃O₈ X‐ray detector exhibits a high sensitivity of 436 µC Gy_air⁻¹ cm⁻² under 120 keV hard X‐ray, a low dark current drift of 2.44 × 10⁻⁹ nA cm⁻¹ s⁻¹ V⁻¹ and a record low detection limit of 8.19 nGy_air s⁻¹ among all oxide X‐ray detectors. Furthermore, the high‐temperature sensitivity of SnTe₃O₈ X‐ray detector is enhanced to 617 µC Gy_air⁻¹ cm⁻² at 175 °C, which is ≈31 times larger than that of the commercial α‐Se. The high thermal stability and stable high‐temperature sensitivity of SnTe₃O₈ single crystal X‐ray detectors have potential applications in high‐temperature environments. The results not only provide an excellent high‐temperature X‐ray detection crystal but also propose an effective method to explore X‐ray detector materials with excellent performances.