Electron-phonon dynamics in 2D carbon based-hybrids XC (X  =  Si, Ge, Sn)

Area of Science:

• Condensed Matter Physics
• Materials Science
• Computational Physics

Background:

• Electron-phonon (e-ph) coupling is crucial for understanding thermal and electronic properties of semiconductors.
• Exploring novel 2D materials like SiC, GeC, and SnC hybrids is key for advanced electronic and optical applications.

Purpose of the Study:

• To investigate the impact of electron-phonon coupling on the electronic band gap and carrier dynamics in SiC, GeC, and SnC hybrids.
• To identify dominant phonon modes responsible for electron scattering and analyze hot carrier thermalization times.

Main Methods:

• Utilizing ab initio perturbation theory to study e-ph coupling effects.
• Calculating electronic band gap thermal dependence and electron line widths.
• Determining contributions of acoustic and optical phonon modes to self-energy.

Main Results:

• SiC and GeC exhibit normal monotonic band gap decrease with temperature; SnC shows anomalous behavior.
• Electron-phonon scattering rates are governed by specific phonon modes (ZA in SiC, ZA/ZO in GeC, ZO in SnC).
• Hot carrier thermalization occurs at 90 fs (SiC), 100 fs (GeC), and 120 fs (SnC).

Conclusions:

• The study provides a detailed understanding of subpicosecond carrier dynamics after illumination without empirical data.
• The investigated 2D materials show potential for low-cost, high-performance optical communication and monitoring.
• Anomalous thermal dependence in SnC highlights unique electronic properties influenced by specific phonon interactions.