Flux-Enabled Synthesis of High-κ Two-dimensional SmTe1.33ClO5 with Ordered Tellurium Vacancies for Efficient Charge Trapping

Abstract Defect engineering through precise control over vacancy distribution and configuration is crucial for tailoring the electronic and optical properties of two-dimensional (2D) materials, yet the synthesis of 2D materials with ordered vacancy superstructures remains a formidable challenge, despite their great potential as efficient charge-trapping media for memory devices. Here, we report the chemical vapor deposition growth of ultrathin high-κ SmTe1.33ClO5 with ordered Te-vacancy superstructures and tunable vacancy periodicities, where alkali-metal chlorides selectively react with Te–O bonds to induce vacancy formation and controllable vacancy ordering. The resulting SmTe1.33ClO5 exhibits an average dielectric constant of ∼16, enabling efficient charge trapping at low operating voltages, while memory devices demonstrate large hysteresis windows, high ON/OFF ratios, excellent endurance, and long retention times, all of which are essential for low-power memory applications. This work establishes a route for constructing ordered vacancy superstructures in 2D materials and introduces a high-κ crystalline platform for future low-power memory applications.