LiZn(OH)CO₃ : A Deep-Ultraviolet Nonlinear Optical Hydroxycarbonate Designed from a Diamond-like Structure

Area of Science:

• Materials Science
• Optoelectronics
• Crystallography

Background:

• Deep-ultraviolet (DUV) nonlinear optical (NLO) crystals are crucial for advanced technologies.
• Challenges in DUV NLO material discovery include balancing NLO effects with wide band gaps and achieving DUV phase-matching.

Purpose of the Study:

• To design and synthesize a novel DUV NLO material with balanced optoelectronic properties.
• To explore hydroxycarbonates as a new class of DUV NLO materials.

Main Methods:

• Utilized a diamond-like structure as a design template.
• Synthesized the new hydroxycarbonate crystal, LiZn(OH)CO₃.
• Performed first-principles calculations to analyze structure-property relationships.

Main Results:

• Successfully synthesized the first DUV NLO hydroxycarbonate, LiZn(OH)CO₃.
• LiZn(OH)CO₃ exhibits a wide band gap (>6.53 eV), strong second harmonic generation (SHG) response (~3.2× KDP), and large birefringence (0.147 at 1064 nm).
• Achieved the shortest DUV phase-matching wavelength (λ_PM <190 nm) among NLO carbonates.

Conclusions:

• LiZn(OH)CO₃ demonstrates excellent DUV NLO performance, overcoming the typical trade-offs.
• The study presents an effective strategy for designing high-performance DUV NLO hydroxycarbonate materials.