The downscaling of complementary metal-oxide-semiconductor technology has produced breakthroughs in electronics, but more extreme scaling has hit a wall of device performance degradation. One key challenge is the development of insulators with high dielectric constant, wide bandgap and high tunnel masses. Here, we show that two-dimensional monocrystalline gadolinium pentoxide, which is devised through combining particle swarm optimization algorithm and theoretical calculations and synthesized via van der Waals epitaxy, could exhibit a high dielectric constant of ~25.5 and a wide bandgap simultaneously. A desirable equivalent oxide thickness down to 1 nm with an ultralow leakage current of ~10⁻⁴ A cm⁻² even at 5 MV cm⁻¹ is achieved. The molybdenum disulfide transistors gated by gadolinium pentoxide exhibit high on/off ratios over 10⁸ and near-Boltzmann-limit subthreshold swing at an operation voltage of 0.5 V. We also constructed inverter circuits with high gain and nanowatt power consumption. This reliable approach to integrating ultrathin monocrystalline insulators paves the way to future nanoelectronics.

互补金属氧化物半导体技术的小型化在电子领域取得了突破，但更极端的微缩已经遇到了器件性能下降的壁垒。一个关键挑战是开发具有高介电常数、宽带隙和高隧道质量的绝缘体。在这里，我们表明，通过结合粒子群优化算法和理论计算设计并通过范德华外延合成的二维单晶五氧化二钆可以同时表现出 ~25.5 的高介电常数和宽禁带。即使在 5 MV ^cm-1 下，也能实现低至 1 nm 的理想等效氧化物厚度和 ~^10-4 A ^cm-2 的超低泄漏电流。由五氧化二钆门控的二硫化钼晶体管在 0.5 V 的工作电压下表现出超过 10：⁸ 的高开/关比和接近玻尔兹曼极限的亚阈值摆幅。我们还构建了具有高增益和纳瓦级功耗的逆变器电路。这种集成超薄单晶绝缘体的可靠方法为未来的纳米电子学铺平了道路。