Bulk Photovoltaic Effect in High-Temperature Lead-Halide Molecular Ferroelectric [C₄N₂H₁₄][PbI₄]

Area of Science:

• Materials Science
• Solid State Physics
• Chemistry

Background:

• Hybrid organic-inorganic molecular ferroelectrics (HOIMFs) are crucial for optoelectronic and spintronic applications.
• Developing HOIMFs with high Curie temperature (Tc), narrow bandgap (Eg), stability, and high breakdown voltage remains a challenge.

Purpose of the Study:

• To synthesize and characterize a novel lead-halide molecular ferroelectric with enhanced properties.
• To investigate its potential for optoelectronic applications, particularly switchable photovoltaics.

Main Methods:

• Hydrothermal synthesis of (1,4-butanediammonium)PbI4 (1).
• Characterization of ferroelectric properties, including Curie temperature, saturation polarization, and coercivity.
• Measurement of bandgap, photovoltaic effect, response time, and breakdown electric field.

Main Results:

• The synthesized material (1) exhibits a high Curie temperature of 485 K and room-temperature ferroelectricity.
• It possesses a direct bandgap of 2.28 eV and semiconductor behavior.
• A switchable photovoltaic effect was observed with a fast response time (∼2 ms) and high breakdown electric field (80 kV/cm), achieving a photovoltage of ∼0.84 V.

Conclusions:

• The novel lead-halide molecular ferroelectric (1) demonstrates excellent properties, including high Tc and switchable photovoltaic effects.
• This material presents a promising platform for developing advanced photodetectors, data storage, and logical switching devices.