| 초록 |
We investigate new ionic nonlinear optical (NLO) materials based on phenolic benzothiazolium cations, OHB ((E)-2-(4-hydroxystyryl)-3-methylbenzo[d]thiazol-3-ium) and DHB ((E)-2-(3,4-dihydroxystyryl)-3-methylbenzo[d]thiazol-3-ium), with p-substituted benzenesulfonate anions, CBS (4-chlorobenzenesulfonate) and T (4-methylbenzenesulfonate). OHB crystals exhibit relatively larger macroscopic nonlinear optical response than DHB crystals, which is confirmed by second harmonic generation (SHG) test. OHB-CBS single crystal is chosen for crystal structure analysis due to suitable solubility properties for growing large-size crystals and relatively high optical nonlinearity. As-grown OHB-CBS crystals have out-of-plane molecular axis and in-plane polar axis, which is not observable at state-of-art organic ionic crystals. This unusual out-of-plane molecular axis may affect the refractive index being important for the phase matching possibilities. |
