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

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.