Two-dimensional Janus SbTeBr/SbSI heterostructures as multifunctional optoelectronic systems with efficient carrier...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) materials stacking is crucial for advanced optoelectronic devices.
• Janus monolayer-based van der Waals heterostructures (vdWHs) offer unique properties for device applications.

Purpose of the Study:

• To investigate the electronic, optical, mechanical, and dynamical properties of a novel SbTeBr/SbSI vdWH.
• To assess the potential of SbTeBr/SbSI for high-performance optoelectronic applications, particularly solar cells.

Main Methods:

• Computational examination of the SbTeBr/SbSI vdWH in its most stable binding configuration.
• Analysis of electronic band structure, optical absorption, and carrier mobility.
• Nonadiabatic molecular dynamics simulations to predict electron-hole recombination time.

Main Results:

• The SbTeBr/SbSI vdWH exhibits a type II band alignment with an indirect bandgap of 1.28 eV.
• Strong visible light absorption (4 × 10^5 cm^-1) and potential for 8.3% power conversion efficiency in solar cells.
• Dipole-induced electric field enhances carrier mobility differences, suppressing photogenerated carrier recombination.
• Predicted long electron-hole recombination time of 133 ps.

Conclusions:

• The SbTeBr/SbSI heterostructure demonstrates efficient charge separation due to its unique electronic and dynamical properties.
• This material shows significant promise for the development of next-generation high-performance optoelectronic devices, including solar cells.