Two scandium borate UV NLO crystals designed through chemical element substitution

Area of Science:

• Inorganic Chemistry
• Materials Science
• Solid-State Chemistry

Background:

• Rare-earth borates are promising materials for nonlinear optics (NLO).
• Developing new UV NLO materials with wide bandgaps and high stability is crucial.
• Rational elemental substitution is a key strategy for designing novel functional materials.

Purpose of the Study:

• To discover and characterize new rare-earth borate UV NLO crystals.
• To investigate the structural and optical properties of Rb$_{4.1}$Na$_{2.9}$SrSc$_{2}$(B$_{5}$O$_{10}$)$_{3}$ (RNSSBO) and Na$_{4}$Rb$_{3}$Sr$_{0.8}$Sc$_{2.2}$(B$_{5}$O$_{10}$)$_{3}$ (NRSSBO).
• To evaluate their potential for applications in nonlinear optics.

Main Methods:

• Rational elemental substitution was employed for crystal design.
• Synthesis and structural characterization of the target compounds.
• Optical property measurements, including UV cutoff and bandgap determination.
• Second harmonic generation (SHG) measurements.

Main Results:

• Two new rare-earth borate compounds, RNSSBO and NRSSBO, were successfully identified.
• RNSSBO exhibits a UV cutoff edge at 192 nm and a wide bandgap of 5.49 eV.
• RNSSBO demonstrates high thermal stability and second harmonic generation (SHG) performance comparable to KDP.

Conclusions:

• RNSSBO and NRSSBO represent new additions to the family of rare-earth borate UV NLO materials.
• RNSSBO possesses excellent optical and thermal properties, making it a promising candidate for UV NLO devices.
• The study highlights the effectiveness of rational elemental substitution in discovering advanced functional materials.