超支化近红外光折变光导聚合物的合成与表征

Organic near-infrared photorefractive materials, especially at the telecommunication wavelength of 1550nm, are currently one challenging subject in organic photoelectric devices due to the great difficulty of organic near-infrared photorefractive response and the potential applications in telecommunication, military, biology, etc. By improving the matching of energy levels between photoconducting polymers, metal-complex photosensitizers and organic plasticizers, the photogenerated carriers may be generated and transported more easily owing to the minishing of hopping energy because the carrier transportation in organic photoconductors follows the hopping mechanism. Consequently, the internal built-up electric field will be strengthened affording the excellent orientation enhancement of organic photorefractive chromophores. The comprehensive performance of organic near-infrared photorefractive devices might be accordingly improved including the shortening of response time, the increase of gain coefficient and diffraction efficiency, etc. Firstly, hyperbranched low-band-gap conjugated polymers with a low glass transition temperature are synthesized as near-infrared photoconducting materials and organic low-band-gap compounds are also prepared as plasticizers to decrease the hopping energy in the process of carrier transportation. Next, in order to increase the carrier generation efficiency under illumination, some soluble metal-dithiene complexes with excellent near-infrared absorption are presented as photosensitizers by enhancing the electron-donating ability of the ligands. Then, these metal-dithiene complexes are incorporated into hyperbranched low-band-gap conjugated polymers to obtain hyperbranched multifunctional photoconducting materials bearing both photosensitivity and photoconduction. Finally, the resulting photoconducting polymers are applied to the photorefractive devices. It is expected that the comprehensive performance of organic photorefractive devices should be improved in the near-infrared region by shortening the response time and enhancing the gain coefficient and diffraction efficiency. The relationship between molecular structure and near-infrared photorefractive property will come into being. Some significant results about organic near-infrared photorefractive materials will be achieved through the comprehensive investigation on organic near-infrared photorefractive devices in this proposal.

近红外光折变器件在光通讯、军事、生物等领域具有重要的潜在应用价值，但实现有机材料的近红外光折变响应却具有相当难度，尤其在长波段近红外光区。本申请拟从改善聚合物光导材料、金属配合物光敏剂、有机增塑剂之间的能级匹配出发，增加近红外光区载流子的产生效率和输运能力，增强有效内建电场，为改善有机光折变色素的取向增强效应提供条件，达到缩短器件响应时间、提高增益因子和衍射效率的目的。首先，合成具有低玻璃化转变温度的超支化低带隙聚合物作为近红外光导材料，合成低带隙小分子化合物作为增塑剂，降低低能量光生载流子的输运壁垒。其次，以提高载流子产生效率为目的，通过对配体的给电子能力进行优化，合成在近红外光区具有优异吸收性能的可溶性硫代双烯金属配合物作为光敏剂，并将其与低带隙聚合物有机结合，制备集敏化与光导于一体的多功能超支化聚合物材料。将上述材料应用于光折变器件制备，期望得到具有优异性能的近红外有机光折变器件。

近红外光折变器件在光通讯、军事、生物等领域具有重要的潜在应用价值，但实现有机材料的近红外光折变响应却具有相当难度，尤其在长波段近红外光区。本申请拟从改善聚合物光导材料、金属配合物光敏剂、有机增塑剂之间的能级匹配出发，增加近红外光区载流子的产生效率和输运能力，增强有效内建电场，为改善有机光折变色素的取向增强效应提供条件，达到缩短器件响应时间、提高增益因子和衍射效率的目的。首先，合成具有低玻璃化转变温度的超支化低带隙聚合物作为近红外光导材料，合成低带隙小分子化合物作为增塑剂，降低低能量光生载流子的输运壁垒。其次，以提高载流子产生效率为目的，通过对配体的给电子能力进行优化，合成在近红外光区具有优异吸收性能的可溶性硫代双烯金属配合物作为光敏剂，并将其与低带隙聚合物有机结合，制备集敏化与光导于一体的多功能超支化聚合物材料。将上述材料应用于光折变器件制备，期望得到具有优异性能的近红外有机光折变器件。.在NSFC-河南联合基金培育项目（No.U1304212）的资助下，我们已经完成了硫代双烯金属配合物近红外光敏剂的合成、小分子低带隙增塑剂的合成、超支化光导聚合物的合成，多功能超支化聚合物的合成已经拿到目标聚合物，其光折变性能的初步表征结果表明：该聚合物在零电场下的二波耦合增益系数约为60cm-1，是一个很好的全光光折变材料，其性能需要进一步优化。在硫代双烯金属配合物近红外光敏剂的合成部分，合成了含咔唑、吩噻嗪、三苯胺基团的镍、钯、铂金属配合物，最大吸收波长在950-1100nm之间，能够满足近红外光敏剂的要求；在小分子低带隙增塑剂的合成部分，其吸收带边波长处在500-700nm之间，表明其能带结构的可调性，可满足光折变器件制备过程中，载流子从光敏剂到光导聚合物、甚至到增塑剂的转移，相关的器件表征工作也正在进行。到目前为止，我们已经发表期刊论文14篇，申请专利3项，正在修改、审稿、整理的文章还有6篇；参加国内外学术会议5次（14人次），发表会议论文14篇；已经申请专利4项；培养博士生5人、硕士生18人；每年接受8-10名本科生做毕业设计。