Thieno[3,4‐c][1,2,5]Thiadiazole‐Based Organic Conjugated Molecules with Visible and Near‐Infrared Dual Emissions for Luminescent Anti‐Counterfeiting Applications

Luminescence materials have gained extensive attention in anti-counterfeiting owing to their unique superiorities. Visible-near infrared (vis-NIR) dual emission that combines naked-eye visible light and concealed NIR light would provide a promising strategy for improving the covertness and secure anti-counterfeiting effect. Here, two organic conjugated materials 4,4′-(thieno[3,4-c[1,2,5thiadiazole-4,6 diyl)bis(N,N-bis(4-(aldehyde)phenyl)aniline) (TTD-TPA-CHO) and 4,4′-(thieno[3,4-c[1,2,5thiadiazole-4,6 diyl)bis(N,N-bis(phenyl)aniline) (TTD-TPA) based on thieno[3,4-c[1,2,5thiadiazole (TT) have been developed, exhibiting vis-NIR dual emissions by manipulating the charge transfer states. With the aid of self-healing technique, stretchable and highly transparent TTD-TPA-CHO and TTD-TPA containing self-healing PDMS films are efficiently prepared to fabricate dual-mode anti-counterfeiting patterns for demonstrating the anti-counterfeiting applications. Under UV light, the luminescent patterns in visible region can be read out by the naked eye, while the concealed information could be accessed by NIR detection devices. These results evidently suggest the important role of vis-NIR dual emission in enhancing the stealth of encrypted information and the security level of anti-counterfeiting. Hopefully, this work would promote the further development of vis-NIR dual-emission organic conjugated materials in anti-counterfeiting techniques.

发光材料由于其独特的优势在防伪领域受到了广泛关注。结合肉眼可见光和隐蔽近红外光的可见 - 近红外（vis - NIR）双发射将为提高隐蔽性和安全防伪效果提供一种有前景的策略。在此，开发了两种基于噻吩并[3,4 - c][1,2,5 - 噻二唑（TT）的有机共轭材料4,4′ - （噻吩并[3,4 - c][1,2,5 - 噻二唑 - 4,6 - 二基）双（N,N - 双（4 - （醛基）苯基）苯胺）（TTD - TPA - CHO）和4,4′ - （噻吩并[3,4 - c][1,2,5 - 噻二唑 - 4,6 - 二基）双（N,N - 双（苯基）苯胺）（TTD - TPA），通过调控电荷转移态呈现出vis - NIR双发射。借助自修复技术，高效制备了含有自修复聚二甲基硅氧烷（PDMS）薄膜的可拉伸且高度透明的TTD - TPA - CHO和TTD - TPA，用于制造双模防伪图案以展示防伪应用。在紫外光下，可见区域的发光图案可由肉眼读取，而隐蔽信息可通过近红外检测设备获取。这些结果明显表明vis - NIR双发射在增强加密信息的隐蔽性和防伪安全级别方面的重要作用。希望这项工作将促进vis - NIR双发射有机共轭材料在防伪技术中的进一步发展。