Electronic and Transport Properties of Ti2CO2 MXene Nanoribbons

Using first-principles calculations, the electronic structures and electron transport properties of zigzag and armchair O-functionalized Ti2C MXene nanoribbons are examined in this work. We demonstrate that the energy gaps in patterned Ti2CO2 nanoribbons can be tuned by appropriate designs of crystallographic orientation and widths. The Ti2CO2 nanoribbons along the zigzag direction with width parameter larger than six show zero or very low band gaps, while band gaps are opened for Ti2CO2 nanoribbons with armchair-shaped edges. The electronic transport properties for the devices of Ti2CO2 nanoribbons with various widths are investigated using nonequilibrium Green's functions, and the current–voltage characteristics of the devices are predicted. The current calculations reveal that some of these devices may have a nonlinear feature as well as negative differential resistance behaviors. The zigzag and armchair Ti2CO2 nanoribbon devices show different current–voltage curves. There are onset biases for armchair Ti2CO2 nanoribbons so that the current is generated due to the band gaps but not for most of the zigzag nanoribbons. The corresponding mechanisms for the variation of electronic band gaps and electronic transport properties are discussed. Based on their excellent carrier mobilities reported for the Ti2CO2 MXene and the negative differential resistance effect found in this work, the Ti2CO2 nanoribbon systems might find promising applications in nanoelectronic devices.