We separate crystal seeds preparation and growth process by substrate-supported rapid evaporation crystallization (SSREC) and saturated vapor cultivation respectively.

In this study, we develop an environmentally friendly one-drop self-assembling method for DAST NWs fabrication.

Although many organic materials have been successfully employed to synthesize second harmonic generation (SHG) active 1D crystalline nanostructures, their second-order susceptibilities are still far lower than those of organic NLO crystals with large dipole moments. For organic materials, the self-assembly driving forces can originate from interactions such as coordination bonding, aromatic π−π stacking, hydrogen bonding, Van der Waals forces, and electrostatic interactions. Meanwhile, self-assembly, a bottom-up technique, is becoming a powerful method for fabricating micro/nanoscale one-dimensional (1D) structures and is promising for the production of miniaturized integrated electronic, optoelectronic, and photonic devices. However, the applications of DAST crystals are limited due to their deficient quality and the difficulty of fabricating DAST crystal optical waveguides using the traditional “top-down” approach. Organic ionic 4-N, N-dimethylamino-4′-N′-methyl-stilbazolium tosylate (DAST) crystals are recognized as benchmark organic NLO crystals due to their electro-optic coefficients γ 11 = 55 ± 80pm/V at 1315 nm , high-NLO susceptibilities χ (2)(−2 ω, ω, ω) = 580 ± 30pm/V at 1535 nm, and low-dielectric constants (5.2, 10 3–10 5 kHz) and consequently are researched intensively. Second-order organic nonlinear optical (NLO) materials have ultra-fast electro-optic response times as well as very large bandwidths and NLO coefficients, and therefore, have been intensively researched for a wide range of applications related to electrical/optical signal transduction, optical switching, phased-array radar, analogue/digital conversion, terahertz signal generation, and digital signal processing.

Nlo properties of crystals