Suppressing Intrinsic Defects via Ag Doping Enables High‐Performance InSe Field‐Effect Transistors

InSe is a highly promising material for the next-generation nanoelectronics due to unique optoelectronic and electronic performance. However, the presence of intrinsic defects plays a detrimental role in InSe field-effect transistors (FETs) and photodetectors, which causes carrier scattering and degrades performance. Herein, we demonstrated an efficient Ag doping strategy in bulk InSe and developed the high-performance Ag-doped InSe FET. Detailed material structural characterization reveal that the doped Ag atoms are filled into Se vacancies, effectively suppressing Se atoms volatilization and improving the crystallinity of Ag-doped InSe. The enhanced lattice structure can effectively suppress carrier scattering and promote electron transport, greatly improving the electrical and photoelectrical performance of multilayer device. Ag-InSe FET presents both significantly superior electrical (three ∼ ten times higher field-effect mobility) and photoelectrical (ten ∼ thousand times higher responsivity) performance compared to undoped InSe and other two dimensional (2D) intrinsic materials devices. This work opens a valuable defect suppressing way to enhance 2D device performance.