Low‐Temperature Controlled Growth of 2D LaOCl with Enhanced Dielectric Properties for Advanced Electronics

Abstract 2D semiconductors are widely regarded as the future of highly integrated circuits, but their commercialization is hindered by the lack of suitable gate dielectrics that meet stringent performance and processing requirements. In this study, a novel LiNO₃‐assisted Confined Flux Growth (CFG) method is presented that enables the synthesis of high‐quality 2D LaOCl nanosheets at remarkably low temperatures (250–350 °C). The synthesized LaOCl not only shows an exciting coexistence of wide bandgap (≈5.54 eV) and high dielectric constant (≈13.8) but also can form high‐quality van der Waals interfaces with 2D semiconductors. Compared to traditional methods, the CFG approach significantly reduces thermal budget, providing opportunities for facile integration with the traditional semiconductor industry. Furthermore, the multifunctional application of LaOCl is demonstrated in 2D transistors. The MoS₂ field‐effect transistors (FET) gated by LaOCl exhibit excellent gate control (on/off ratio >10⁸) and low interfacial trap density. The floating‐gate devices with LaOCl as the tunneling layer show an extremely large storage window (≈91%) and stable storage characteristics. These findings establish 2D LaOCl as a transformative dielectric material, paving the way for next‐generation multifunctional 2D electronic devices.