Molecule-based nonlinear optical switch with highly tunable on-off temperature using a dual solid solution approach

Shi-Yong Zhang,Chun-Ting He,Xiao-Ming Chen,Qing-Yan Liu,Wei-Xiong Zhang,Xia Shu,Ying Zeng,Zi-Yi Du

doi:10.1038/s41467-020-15518-z

Shi-Yong Zhang, Chun-Ting He + Show 6 more

Open Access

https://doi.org/10.1038/s41467-020-15518-z

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Abstract

Nonlinear optical switches that reversibly convert between on/off states by thermal stimuli are promising for applications in the fields of photoelectronics and photonics. Currently one main drawback for practical application lies in the control of their switch temperature, especially for the temperature range near room temperature. By mixed melting treatment, here we describe an alloy-like nonlinear optical switch with tunable switch temperature via a dual solid solution approach within the coordination polymer system. We initially prepare a coordination polymer (i-PrNHMe2)[Cd(SCN)3], which functions as a high-contrast thermoresponsive nonlinear optical switch originating from a phase transition at around 328 K. Furthermore, by taking advantage of a synergistic dual solid solution effect, the melt mixing of it with its analogue (MeNHEt2)[Cd(SCN)3], which features an unequal anionic chain templated by an isomeric ammonium, can afford coordination polymer solid solutions with switch temperatures that are tunable in a range of 273–328 K merely by varying the component ratio.

Highlights

Nonlinear optical switches that reversibly convert between on/off states by thermal stimuli are promising for applications in the fields of photoelectronics and photonics
Most of the reported thermoresponsive Nonlinear optical (NLO) switches do not have the tunability on the regulation of their on-off temperatures (TS), especially for the temperature range above and below the room temperature, which is a key issue for practical application
To resolve the above issue, the formation of coordination polymers (CPs) solid solutions or alloys that retain a similar structure to the NLO-switchable parent phase may be an efficient and convenient method, of which the TS could be finely tuned by the varied ratio of such binary system

Summary

Introduction

Nonlinear optical switches that reversibly convert between on/off states by thermal stimuli are promising for applications in the fields of photoelectronics and photonics. One most feasible method is to tweak the conformation or orientation of NLOchromophore molecules in the crystal structures by thermal stimulus, with a mechanism related to structural phase transition, which can realign the NLO-active moieties to alter the SHG signal, especially those with the transition from a noncentrosymmetric space group to a centrosymmetric one[2,10,11,12,13,14,15,16,17,18,19,20] Following this strategy, the thermoresponsive NLO switches within the molecule-based systems, typically represented by the coordination polymers (CPs), can be achieved with many advantages such as the designable and flexible structures, the relatively mild preparation condition as well as appropriate on/off contrast of SHG signal. Tphase transition cation lead mixed-halide perovskite[38], we conceive that a synchronous dual mixing strategy, i.e., the Mode 3, may shift the tunable scope to lower temperature range, which is somewhat similar to the melting point reduction effect of common metal alloys due to the weakening interatomic forces

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