Pressure‐Driven Two‐Step Second‐Harmonic‐Generation Switching in BiOIO₃

Abstract

Materials with multi-stabilities controllable by external stimuli have potential for high-capacity information storage and switch devices. Herein, we report the observation of pressure-driven two-step second-harmonic-generation (SHG) switching in polar BiOIO 3 for the first time. Structure analyses reveal two pressure-induced phase transitions in BiOIO 3 from the ambient noncentrosymmetric phase (SHGhigh) to an intermediate noncentrosymmetric phase (SHGintermediate) and then to a centrosymmetric phase (SHGoff). The three-state SHG switching was inspected by in situ high-pressure powder SHG and polarization-dependent single-crystal SHG measurements. Local structure analyses based on the in situ Raman spectra and X-ray absorption spectra reveal that the SHG switching is caused by the stepwise suppression of lone-pair electrons on the [IO 3 ] À units. The dramatic evolution of the functional units under compression also leads to subtle changes of the optical absorption edge of BiOIO 3 . Materials with switchable multistabilities provide a state-of-art platform for next-generation switch and information storage devices.

Emission Dipole and Pressure‐Driven Tunability of Second Harmonic Generation in vdWs Ferroelectric NbOI2

“…When hydrostatic pressure is applied to the materials, the volume of the unit cell would decrease, with the increasing the stiffness coefficient of chemical bonds. The relationship between Raman frequency and the pressure can be written as: [54][55][56]…”

Dynamic Co(µ‐O)2Ru Moiety Endowed Efficiently Catalytic Hydrogen Evolution

“…[12] However, although a large number of highly active Rubased electrocatalysts have been acknowledged in this field, it is still inadequate how synergistic effect can promote the HER performance, especially for corresponding potential-driven reactive sites at the atomic level. [13] Regarding the advanced in situ techniques, ongoing characterization efforts employing X-ray absorption spectroscopy (XAS) have successfully unveiled the potential-induced [14] or pressure-driven [15] changes in local geometry of the active sites.…”

Nonlinear Optical Properties of Pyrene Derivatives Based on a Donor–Acceptor Structure and Its Polyurethane Composites

“… 2 − 6 In recent years, nonlinear optical materials have potential applications in optical information storage, all-optical switching, fluorescence microscopy, photodynamic therapy, etc. 7 − 12 Nonlinear optical materials were first studied from inorganic materials, such as KTiOPO 4 (KTP) type materials, KH 2 PO 4 (KDP) type materials, perovskite type materials, borate materials, and so on. 13 − 15 Although inorganic materials as nonlinear optical materials have the advantages of good chemical stability, processing performance, and high frequency doubling conversion rate, the long-term development of inorganic materials is limited by the disadvantages of low damage threshold, low nonlinear response, and difficulty processing into devices.…”

“…In 1961, Franken passed a pulse generated by a ruby laser through quartz crystal and observed the second harmonic for the first time. With the discovery of nonlinear optical phenomena such as stimulated Raman scattering, parametric oscillation, reverse saturation absorption, self-phase modulation, and so on, the research of nonlinear optics and related applications has developed at an unprecedented speed. − In recent years, nonlinear optical materials have potential applications in optical information storage, all-optical switching, fluorescence microscopy, photodynamic therapy, etc. − Nonlinear optical materials were first studied from inorganic materials, such as KTiOPO 4 (KTP) type materials, KH 2 PO 4 (KDP) type materials, perovskite type materials, borate materials, and so on. − Although inorganic materials as nonlinear optical materials have the advantages of good chemical stability, processing performance, and high frequency doubling conversion rate, the long-term development of inorganic materials is limited by the disadvantages of low damage threshold, low nonlinear response, and difficulty processing into devices. People’s vision has gradually shifted from inorganic materials to organic materials.…”