Theoretical exploration of the multifunctional applications of Sc₂CT₂ (T = F, O) MXenes: p-n junction diodes, field effect transistors, and phototransistors

This study systematically examines the electronic and mechanical properties of two-dimensional MXene Sc₂CT₂ (T = F, O) monolayers and investigates the electronic transport and optoelectronic properties of several nanodevices, including p-n junction diodes, field-effect transistors (FETs), and phototransistors. The results demonstrate that Sc₂CT₂ exhibits robust dynamic, thermal, and mechanical stabilities, with moderate bandgaps of 1.72 eV (Sc₂CF₂) and 2.04 eV (Sc₂CO₂), positioning it as a promising semiconductor for nanoelectronics. The p-n junction diodes of Sc₂CT₂ monolayers demonstrated significant rectification effect and electrical anisotropy, with Z-type Sc₂CF₂ diodes achieving a current density of 2000 mA/mm under reverse bias. In addition, the FETs exhibit gate-voltage-modulated current variations. Also, the Sc₂CT₂ monolayers and phototransistors show good photoelectric responses in the visible and ultraviolet regions. Notably, the Sc₂CO₂ phototransistors achieve isotropic photocurrents up to 0.6 mA/mm² in the ultraviolet region. These findings underscore Sc₂CT₂'s multifunctional potential in next-generation nanodevices, providing theoretical insights for optimizing MXene-based semiconductor designs.