Nonlinear Optical Glass‐Ceramic From a New Polar Phase‐Transition Organic‐Inorganic Hybrid Crystal

Abstract

Melt‐quenched glasses of organic–inorganic hybrid crystals, i.e., hybrid glasses, have attracted increasing attention as an emerging class of hybrid materials with beneficial processability and formability in the past years. Herein, we present a new hybrid crystal, (Ph3PEt)3[Ni(NCS)5] (1, Ph3PEt+=ethyl(triphenyl)phosphonium), crystallizing in a polar space group P1 and exhibiting thermal‐induced reversible crystal‐liquid‐glass‐crystal transitions with relatively low melting temperature of 132 °C, glass‐transition temperature of 40 °C, and recrystallization on‐set temperature of 78 °C, respectively. Taking advantage of such mild conditions, we fabricated an unprecedented hybrid glass‐ceramic thin film, i.e., a thin glass uniformly embedding inner polar micro‐crystals, which exhibits a much enhanced intrinsic second‐order nonlinear optical effect, being ca. 25.6 and 3.1 times those of poly‐crystalline 1 and KH2PO4, respectively, without any poling treatments.

Reversible Phase Transition and Dielectric Response of Hybrid Lead-Free Antimony-Based Crystals

“…Recently, there has been a notable increase in interest regarding organic–inorganic hybrid phase transition materials. The intriguing thermodynamic and kinetic properties of these hybrid compounds, coupled with their diverse structures, bestow upon them a range of fascinating physical phenomena and characteristics. − Consequently, numerous research fields have dedicated their efforts to exploring these materials in the pursuit of exciting discoveries and novel features. Moreover, organic–inorganic hybrid halide counterparts have captured equal attention due to their versatility, solution-processability, and structural tunability. − These compounds have showcased an outstanding performance in various areas such as dielectric, ferroelectric, piezoelectric, photoluminescent, thermochromic, and nonlinear optics. − Importantly, the properties of phase transition materials are closely tied to their molecular structure.…”