Silver/Antimony-Base Multifunctional Double Perovskite with H/F Substitution Enhance Properties

Area of Science:

• Materials Science
• Solid-State Chemistry
• Optoelectronics

Background:

• Two-dimensional (2D) double perovskites are rapidly advancing due to their unique optoelectronic properties and structural diversity.
• Challenges remain in synthesizing high-performance multifunctional compounds and precisely controlling their properties.

Purpose of the Study:

• To synthesize novel multifunctional 2D double perovskite compounds.
• To investigate the impact of hydrogen/fluorine (H/F) substitution on material properties.
• To explore the emission mechanisms and potential applications of these compounds.

Main Methods:

• Synthesis of two new compounds: (C6H14N)4AgSbBr8 (1) and (F2-C6H12N)4AgSbBr8 (2).
• Characterization of solid-state phase transition temperature and dielectric properties.
• Investigation of optical properties, including second harmonic generation (SHG) and photoluminescence.
• First-principles calculations and variable-temperature fluorescence spectroscopy to elucidate emission mechanisms.

Main Results:

• Successfully synthesized two multifunctional 2D double perovskites with high solid-state phase transition temperatures.
• Demonstrated bistable dielectric constant switching and significant second harmonic generation (SHG).
• Achieved bright emission, with H/F substitution increasing transition temperature and reducing band gap due to decreased interlayer spacing.
• Confirmed the presence of self-trapped exciton emission (STE1) as the broad emission mechanism.

Conclusions:

• The synthesized compounds exhibit promising multifunctional properties for advanced applications.
• H/F substitution is an effective strategy for tuning phase transition temperatures and electronic band gaps in 2D double perovskites.
• Understanding the emission mechanism provides a foundation for designing next-generation optoelectronic materials.