Beyond 22% power conversion efficiency in type-II MoSi₂As₄/MoGe₂N₄ photovoltaic vdW heterostructure

Area of Science:

• Materials Science
• Condensed Matter Physics
• Renewable Energy

Background:

• Advanced solar cell materials, including 2D materials and van der Waals (vdW) heterostructures, are crucial for enhancing photovoltaic efficiency and reducing costs.
• Current challenges include improving light absorption, carrier mobility, and power conversion efficiency (PCE).

Purpose of the Study:

• To develop and investigate a novel 2D MoSi2As4/MoGe2N4 vdW heterostructure for solar cell applications.
• To evaluate its optoelectronic properties, including band alignment, charge transfer, stability, optical absorption, and carrier mobility.

Main Methods:

• Computational modeling was used to construct and analyze the 2D MoSi2As4/MoGe2N4 vdW heterostructure.
• Key properties such as band gap, band alignment, charge carrier dynamics, optical absorption, and electron mobility were calculated.

Main Results:

• The MoSi2As4/MoGe2N4 heterostructure exhibits an indirect band gap of 1.14 eV and type-II band alignment, facilitating efficient electron-hole separation.
• It demonstrates excellent stability, broad optical absorption up to 10^5 cm^-1, high electron mobility (9065 cm^2 V^-1 s^-1), and minimal recombination.
• A high power conversion efficiency (PCE) of up to 22.09% was predicted.

Conclusions:

• The 2D MoSi2As4/MoGe2N4 vdW heterostructure possesses superior optoelectronic properties.
• It represents a promising candidate material for next-generation high-performance solar cells.