Isoreticular Design of KTiOPO4-Like Deep-Ultraviolet Transparent Materials Exhibiting Strong Second-Harmonic Generation

Chunbo Jiang; Xingxing Jiang; Chao Wu; Zhipeng Huang; Zheshuai Lin; Mark G Humphrey; Chi Zhang

doi:10.1021/jacs.2c08403

Isoreticular Design of KTiOPO₄-Like Deep-Ultraviolet Transparent Materials Exhibiting Strong Second-Harmonic Generation

J Am Chem Soc. 2022 Nov 9;144(44):20394-20399. doi: 10.1021/jacs.2c08403. Epub 2022 Oct 19.

Authors

Chunbo Jiang¹, Xingxing Jiang², Chao Wu¹, Zhipeng Huang¹, Zheshuai Lin², Mark G Humphrey³, Chi Zhang¹

Affiliations

¹ China-Australia Joint Research Center for Functional Molecular Materials, School of Chemical Science and Engineering, Tongji University, Shanghai 200092, China.
² Key Lab of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
³ Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory 2601, Australia.

PMID: 36260708
DOI: 10.1021/jacs.2c08403

Abstract

Second-harmonic generation (SHG) is of great technological importance for applications in nonlinear optics, but it remains challenging to engineer large SHG responses in the short-wavelength ultraviolet (UV) region owing to competing microstructure requirements. Herein, we report the first examples of d⁰ transition-metal-based (TM-based) deep-UV-transparent nonlinear optical (NLO) crystals MOF₄H₂ (M = Zr (ZOF), Hf (HOF)), which exhibit unprecedented short UV absorption edges (below 190 nm). Evolving from the KTiOPO₄ (KTP) structure by an isoreticular node substitution strategy, the three-dimensional frameworks of ZOF and HOF consist of corner-sharing [MO₂F₆] moieties that are new functional units in deep-UV NLO material design, conferring wide UV transparency and strong phase-matchable SHG response (2.2 × KH₂PO₄ (ZOF) and 1.8 × KH₂PO₄ (HOF) at 1064 nm). Such d⁰-TM-based [MO₂F₆] polyhedra preclude deleterious d-d electronic transitions, resulting in significantly blue-shifted UV absorption edges of ZOF and HOF (<190 nm). The d⁰-TM-based [MO₂F₆] polyhedra introduced in this work offer a new perspective in the construction of deep-UV transparent NLO materials, demonstrating the feasibility of an isoreticular design strategy in developing functional NLO materials.