Two-dimensional IV-VA₃ monolayers with enhanced charge mobility for high-performance solar cells.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Renewable Energy

Background:

• Silicon (Si)-based solar cells (SCs) dominate the photovoltaic market but suffer from limited carrier mobility, hindering device efficiency.
• Developing advanced photovoltaic materials is crucial for high-performance solar energy conversion.

Purpose of the Study:

• To computationally investigate novel two-dimensional (2D) group IV and V compounds with an AX3 configuration for high-performance photovoltaics (PVs).
• To assess the feasibility of experimental exfoliation and evaluate the electronic, optical, and charge transport properties of these 2D materials.

Main Methods:

• Density functional theory (DFT) calculations were employed to determine physicochemical and PV performance.
• Cleavage energies were computed to assess exfoliation potential.
• Electronic band structures, optical absorption spectra, and carrier mobilities were systematically analyzed.

Main Results:

• AX3 compounds (A = Si, Ge; X = P, As, Sb) exhibit cleavage energies below 1 J m⁻², indicating experimental exfoliation feasibility.
• Monolayer AX3 materials possess band gaps (1.11–1.27 eV) comparable to silicon.
• Electron mobility in monolayer AX3 can exceed 30,000 cm² V⁻¹ s⁻¹, an order of magnitude higher than silicon.
• SiAs3, SiP3, and GeAs3 monolayers show high optical absorbance in the visible spectrum.

Conclusions:

• The designed 2D AX3-based PV systems demonstrate potential for high power conversion efficiencies (up to 20%).
• These novel materials offer a promising alternative to silicon for next-generation high-performance photovoltaics.
• The findings highlight the potential of 2D group IV and V compounds in advancing solar energy technology.