Highly efficient neutron detectors are critical in many sectors, including national security^1,2, medicine³, crystallography⁴ and astronomy⁵. The main neutron detection technologies currently used involve ³He-gas-filled proportional counters⁶ and light scintillators⁷ for thermalized neutrons. Semiconductors could provide the next generation of neutron detectors because their advantages could make them competitive with or superior to existing detectors. In particular, solids with a high concentration of high-neutron-capture nuclides (such as ⁶Li, ¹⁰B) could be used to develop smaller detectors with high intrinsic efficiencies. However, no promising materials have been reported so far for the construction of direct-conversion semiconductor detectors. Here we report on the semiconductor LiInP₂Se₆ and demonstrate its potential as a candidate material for the direct detection of thermal neutrons at room temperature. This compound has a good thermal-neutron-capture cross-section, a suitable bandgap (2.06 electronvolts) and a favourable electronic band structure for efficient electron charge transport. We used α particles from an ²⁴¹Am source as a proxy for the neutron-capture reaction and determined that the compact two-dimensional (2D) LiInP₂Se₆ detectors resolved the full-energy peak with an energy resolution of 13.9 per cent. Direct neutron detection from a moderated Pu–Be source was achieved using ⁶Li-enriched (95 per cent) LiInP₂Se₆ detectors with full-peak resolution. We anticipate that these results will spark interest in this field and enable the replacement of ³He counters by semiconductor-based neutron detectors.

高效中子探测器在许多领域都至关重要，包括国家安全^1,2、医学³、晶体学⁴和天文学⁵。目前使用的主要中子探测技术包括³个充氦气的比例计数器⁶和用于热化中子的光闪烁器^{7 。}半导体可以提供下一代中子探测器，因为它们的优势可以使它们与现有探测器竞争或优于现有探测器。特别是具有高浓度高中子俘获核素（如⁶ Li、¹⁰B) 可用于开发具有高内在效率的小型探测器。然而，到目前为止，还没有报道用于构建直接转换半导体探测器的有前景的材料。在这里，我们报告了半导体 LiInP ₂ Se ₆并展示了其作为在室温下直接检测热中子的候选材料的潜力。该化合物具有良好的热中子俘获截面、合适的带隙（2.06 电子伏特）和有利的电子能带结构，可实现有效的电子电荷传输。^{我们使用来自241} Am 源的α 粒子作为中子俘获反应的代表，并确定致密二维 (2D) LiInP ₂ Se ₆探测器以 13.9% 的能量分辨率解析了全能量峰值。使用⁶_个具有全峰值分辨率的富锂（95%）LiInP ₂ Se ₆探测器实现了对缓和的 Pu-Be 源的直接中子探测。我们预计这些结果将激发对该领域的兴趣，并使基于半导体的中子探测器能够取代³ He 计数器。