2D ferroelectric AgInP₂Se₆ for Ultra‐Steep Slope Transistor with SS Below 10 mV Decade⁻¹

Abstract Along with continuous size shrinking, conventional silicon based transistors face the the challenges of both manufacture complexity and physical limitations. The negative capacitance transistors (NC‐FETs) using 2D ferroelectric materials as dielectric insulators are emerging as reliable solutions owing to their advantages of breaking the Boltzmann limitation and Complementary Metal‐Oxide Semiconductor (CMOS) compatibility. Here, the room temperature ferroelectricity of 2D AgInP 2 Se 6 is discovered which is further integrated with MoS 2 channel into ultra‐steep NC‐FETs for low‐power electronic applications. Due to the negative capacitance effect of AgInP 2 Se 6 during the polarization reversal process, the transistor breaks the Boltzmann limitation with a subthreshold swing (SS) of less than 10 mV decade −1 . By optimizing the thickness of AgInP 2 Se 6 , superior transistor performance with a minimum SS of 7.75 mV dec −1 and a high on/off ratio of up to 5.88 × 10 4 can be achieved. This work develops a new 2D ferroelectric AgInP 2 Se 6 with room temperature ferroelectricity, providing promising material platforms for small‐size, ultra‐steep, and low‐power electronics.