Deep-ultraviolet transparent phosphates RbBa2(PO3)5 and Rb2Ba3(P2O7)2 show nonlinear optical activity from condensation of [PO4](3-) units

Sangen Zhao; Pifu Gong; Siyang Luo; Lei Bai; Zheshuai Lin; Chengmin Ji; Tianliang Chen; Maochun Hong; Junhua Luo

doi:10.1021/ja504319x

Deep-ultraviolet transparent phosphates RbBa2(PO3)5 and Rb2Ba3(P2O7)2 show nonlinear optical activity from condensation of [PO4](3-) units

J Am Chem Soc. 2014 Jun 18;136(24):8560-3. doi: 10.1021/ja504319x. Epub 2014 Jun 10.

Authors

Sangen Zhao¹, Pifu Gong, Siyang Luo, Lei Bai, Zheshuai Lin, Chengmin Ji, Tianliang Chen, Maochun Hong, Junhua Luo

Affiliation

¹ Key Laboratory of Optoelectronic Materials Chemistry and Physics and ∥State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences , Fuzhou, Fujian 350002, China.

PMID: 24906077
DOI: 10.1021/ja504319x

Abstract

It is challenging to explore deep-ultraviolet (deep-UV) nonlinear optical (NLO) materials that can achieve a subtle balance between deep-UV transparency and high NLO activity. Known deep-UV NLO materials are almost exclusively limited to borates, except few newly discovered phosphates despite their small NLO activities. Here we report two asymmetric phosphates, RbBa2(PO3)5 (I) and Rb2Ba3(P2O7)2 (II), which feature [PO3]∞ chains and [P2O7](4-) dimers formed by condensation of [PO4](3-) units, respectively. Remarkably, I achieves the desired balance, with the shortest deep-UV absorption edge at 163 nm and the largest NLO activity of 1.4 × KDP (KH2PO4) in deep-UV NLO phosphates. According to first-principles calculations, the enhanced macroscopic SHG response of I can be attributed to the [PO3]∞ chains which exhibit significantly larger microscopic SHG coefficients as compared with the [P2O7](4-) dimers.