4- N , N -dimethylamino-4′-N′-methyl-stilbazolium tosylate (DAST) is one of the most important organic nonlinear optical (NLO) materials, but its controlled growth remains a challenge. Herein, we describe a novel method to control the growth of DAST on the surfaces of indium tin oxides coated with the patterned photoresists by electric field. Results indicate that zero-dimensional (0D) spherical DAST microcrystals tend to grow along the photoresist lines if an electric field with a low frequency of 500 Hz is applied. Rather differently, one-dimensional (1D) DAST microwires preferentially grow along the gaps of the photoresist lines under the control of an electric field with a high frequency of 1000 Hz. Growth of DAST microcrystals controlled by electric field leads to the increase in the crystallinity, but the chemical structures remain unchanged. Moreover, second harmonic generation signal was measured from the as-grown DAST microcrystals. The results presented in this work are helpful for rationally controlling the growth of 0D or 1D DAST microcrystals, and particularly, the strategy can be further expanded to control the growth of DAST derivatives or other organic NLO materials with similar chemical structures.

中文翻译：

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4-N,N-二甲氨基-4'-N'-methyl-stilbazolium tosylate (DAST) 有机微晶的电控生长

4-N,N-二甲氨基-4'-N'-甲基-芪唑鎓甲苯磺酸盐（DAST）是最重要的有机非线性光学（NLO）材料之一，但其可控生长仍然是一个挑战。在此，我们描述了一种通过电场控制涂有图案化光刻胶的氧化铟锡表面上 DAST 生长的新方法。结果表明，如果施加 500 Hz 的低频电场，则零维 (0D) 球形 DAST 微晶倾向于沿着光刻胶线生长。不同的是，一维 (1D) DAST 微线在 1000 Hz 高频电场的控制下优先沿着光刻胶线的间隙生长。受电场控制的 DAST 微晶的生长导致结晶度增加，但化学结构保持不变。此外，从生长的 DAST 微晶测量二次谐波产生信号。这项工作中提出的结果有助于合理控制 0D 或 1D DAST 微晶的生长，特别是，该策略可以进一步扩展以控制 DAST 衍生物或其他具有相似化学结构的有机 NLO 材料的生长。