All-organic composites with strong photoelectric response over a wide spectral range

在宽光谱范围内具有强光电响应的全有机复合材料

2-hydroxynaphthylidene-1′-naphthylamine(HNAN) and –NO_(2) modified HNAN(HNAN-NO_(2)) Schiff base compounds were synthesized and exhibited strong visible light absorption(<650 nm). These compounds were added to poly(vinylidene fluoride-trifluoroethylene)(P(VDF-Tr FE))ferroelectric polymer, obtaining composites with high photoelectric response under visible and infrared light. It was found that the modification of HNAN by the nitro group and the poling of the composites under a high electric field can greatly enhance the photoelectric response of the composites. The composites can generate high photovoltages of 1386 and352.7 mV under irradiation with near-infrared light(915 nm)and green light(532 nm). The mechanism of the photoelectric response of the composites under green light was explored and it was found that the response originates mainly from the coupling effect of the photothermal effect of the Schiff base and the pyroelectric effect of the ferroelectric polymer. The composites, which can be utilized as photodetector materials,are promising for next-generation artificial retina applications and the sensing capability of retina can be extended in a wide wavelength range from visible to infrared light.

本文合成了席夫碱化合物2-hydroxynaphthylidene-1′-naphthylamine (HNAN)和硝基改性的HNAN (HNAN-NO_(2)).这两种化合物在可见光(<650 nm)下显示出强吸光性.我们将这些化合物与Poly(vinylidene fluoride-trifluoroethylene)(P(VDF-Tr FE))铁电聚合物复合,得到了在可见光和红外光下具有高光电响应的复合材料.研究发现,利用HNAN的硝基改性或高电场下对复合材料进行极化可以大大增强复合材料的光电响应.复合材料在近红外光(波长915 nm)下可产生1386 mV的光电压,而在绿光(532 nm)下可产生352.7 mV的光电压.本文还探索了复合材料在绿光下的光电响应的产生机理,发现其响应主要源于席夫碱的光热效应和铁电聚合物的热释电效应之间的耦合作用.该复合材料可作为光电材料应用于下一代人工视网膜的光响应材料,并使人工视网膜能够感知的光波段从可见光扩展到红外光.