The authors of the title paper (Optics and Laser Technology 107 (2018) 428–434) report to have grown a so-called ‘thiourea borate’ crystal by slow evaporation of an aqueous solution containing thiourea and boric acid, and have also described the electrical properties of ‘thiourea borate’ (Journal of Electronic Materials, 48 (2019) 5632–5639). In this Letter to the Editor, we prove that the ‘thiourea borate’ is a dubious crystal. Hence all claims of nonlinear optical (NLO) properties of this material are untenable.

中文翻译：

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对论文的评论：“高效半有机晶体：硫脲硼酸盐的线性和非线性光学性质分析”

标题文件的作者（Optics and Laser Technology 107（2018）428–434）报告说，通过缓慢蒸发含有硫脲和硼酸的水溶液，可以生长出所谓的“硫脲硼酸盐”晶体，并且还描述了``硫脲硼酸盐''的电性能（电子材料杂志，48（2019）5632-5639）。在写给编辑的信中，我们证明“硫脲硼酸盐”是可疑的晶体。因此，关于这种材料的非线性光学（NLO）特性的所有主张都是站不住脚的。