Band-like Optical Signatures of Ti 3 C 2 T x MXenes

MXenes have shown great potential in electronic and optoelectronic applications. However, the optical properties of these highly conductive two-dimensional materials are not fully understood. The broad near-infrared (IR) optical extinction (∼1.5 eV) in Ti3C2Tx with mixed terminations (Tx: ═O, −OH, −F, −Cl) has been widely attributed to a localized surface plasmon resonance (LSPR). However, previous simulations suggest this peak may be due to an interband transition (IBT). Here, we show that the real component of the dielectric constant of Ti3C2Tx at this peak is positive (ε1 > 0), as measured by spectroscopic ellipsometry (SE), ruling out the possibility of LSPR. Moreover, this band nearly vanishes for…

• NS
  National Science Foundation

  Awards: CMMI-2134607, CHE-2318105, CHE-2303044
• UO
  University of Pennsylvania
• NC
  Narodowe Centrum Nauki

  Award: 14 2024/54/E/ST11/00171
• NC
  Narodowe Centrum Badań i Rozwoju

  Award: LIDER/8/0055/L-12/20/NCBR/2021