Exploring Aqueous Solution-Processed Pseudohalide Rare-Earth Double Perovskite Ferroelectrics toward X-Ray Detection...

Area of Science:

• Materials Science
• Solid-State Physics
• Crystallography

Background:

• Three-dimensional (3D) pseudohalide rare-earth double perovskites (PREDPs) are known for ferroelectricity, ferroelasticity, piezoelectricity, and circularly polarized luminescence.
• Their application in X-ray detection is unexplored, and low Curie temperatures (T_C) limit their ferroelectric performance window.

Purpose of the Study:

• To synthesize novel 3D PREDP ferroelectrics with enhanced properties.
• To investigate the X-ray detection capabilities of these new materials.
• To understand the structure-composition-functionality relationship in ferroelectric materials.

Main Methods:

• Chemical regulation strategies including halogen substitution on the organic cation and Rb/Cs substitution.
• Synthesis of a novel 3D PREDP ferroelectric [(R)-CM3HQ]₂CsEu(NO₃)₆.
• Fabrication of centimeter-sized single crystals from aqueous solutions.

Main Results:

• A novel 3D PREDP ferroelectric, [(R)-CM3HQ]₂CsEu(NO₃)₆, was synthesized with a T_C of 344 K, an increase from the precursor's 285 K.
• The material demonstrated significant X-ray detection capabilities with a sensitivity of 1307 μC G y_air^-1 cm^-2 and a low detectable dose rate of 152 nGy_air s^-1.
• Achieved the highest sensitivity reported for hybrid double perovskite ferroelectric detectors.

Conclusions:

• The chemical regulation strategy successfully enhanced the T_C and introduced X-ray detection capabilities in PREDPs.
• PREDPs are promising candidates for next-generation eco-friendly optoelectronic materials.
• The findings provide insights into tailoring ferroelectric material properties through structural and compositional modifications.