Defect Imide Double Antiperovskites AE₅AsPn(NH)₂ (AE=Ca, Sr; Pn=Sb, Bi) as Potential Solar Cell Absorber Materials

Area of Science:

• Materials Science
• Solid-State Chemistry
• Inorganic Chemistry

Background:

• Perovskites, particularly oxide, halide, and chalcogenide types, are well-studied.
• Nitride perovskites are rare due to synthesis challenges.
• Ternary antiperovskite nitrides (X3AN) show promise for optoelectronics.

Purpose of the Study:

• To explore new nitride perovskite compositions.
• To synthesize novel layered quaternary imide-based defect-antiperovskites.
• To investigate their structural, electronic, and optical properties for potential solar cell applications.

Main Methods:

• Ammonothermal synthesis method.
• Structural characterization of new compounds.
• Density functional theory (DFT) calculations for property analysis.

Main Results:

• Three new compounds, AE5AsPn(NH)2 (AE=Ca, Sr; Pn=Sb, Bi), were synthesized.
• These compounds feature layered structures with distorted square-pyramidal imide coordination and Ca2+ vacancies.
• DFT calculations revealed suitable direct band gaps, favorable band dispersion, and charge transport properties.

Conclusions:

• The synthesized AE5AsPn(NH)2 compounds possess tunable direct band gaps within the visible spectrum.
• Favorable electronic transport and optical properties suggest potential for 3D electronic behavior.
• These novel materials are promising candidates for solar cell absorber applications.