Colour selective organic photodetectors utilizing ketocyanine-cored dendrimers
Colour selective organic photodetectors utilizing ketocyanine-cored dendrimers
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DOI：
10.1039/c3tc30472h
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发表时间：
2013-01-01
影响因子：
6.4
通讯作者：
Burn, Paul L.
中科院分区：
文献类型：
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作者：
Jansen-van Vuuren, Ross D.;Pivrikas, Almantas;Burn, Paul L.
图像传感器的精确颜色再现需要四个窄带吸收光电检测器（蓝色、绿色、黄色和红色），并且这通常通过使用宽带光电检测器和滤色器来实现。我们已经开发了一种有机光电探测器，其中颜色选择是通过光吸收层的检测器来实现的。光活性层由绿色吸收酮花青染料芯的树枝状聚合物组成，树枝状分子提供溶液可加工性并防止固态聚集，否则聚集会导致吸收光谱的加宽。光敏树枝状大分子的性质被发现是依赖于连接点和树枝的数量。最好的光电探测器含有本体异质结（BHJ）光吸收层，其由树枝状聚合物组成，树枝状聚合物具有两个第一代基于联苯的树枝状基元，所述树枝状基元连接到与[6，6]-苯基-C-61-丁酸甲酯（PC 60 BM）共混的酮花青染料的氮原子。该光电探测器具有以500 nm为中心的130 nm响应的半峰全宽（FWHM）、-1 V下8.2%的外部量子效率（EQE）和迄今为止报道的绿色吸收有机光电探测器的最大整流比（0 V下2.7 × 10（4））。光电探测器的性能被发现接近当前机器视觉系统所需的性能。
Accurate colour reproduction by image sensors requires four narrow-band absorbing photodetectors (blue, green, yellow and red), and this is generally achieved by using a broadband photodetector and colour filters. We have developed an organic photodetector in which colour selection is achieved by the light-absorbing layer of the detector. The photoactive layer is comprised of a green absorbing ketocyanine dye-cored dendrimer with the dendrons providing solution processability and prevention of aggregation in the solid-state, which can otherwise lead to the broadening of the absorption spectrum. The properties of the photoactive dendrimer were found to be dependent on the attachment point and number of dendrons. The best photodetector contained a bulk heterojunction (BHJ) light-absorbing layer comprised of the dendrimer with two first generation biphenyl-based dendrons attached to the nitrogen atoms of the ketocyanine dye blended with [6,6]-phenyl-C-61-butryic acid methyl ester (PC60BM). The photodetector had a Full Width at Half Maximum (FWHM) of the response of 130 nm centred around 500 nm, an External Quantum Efficiency (EQE) of 8.2% at -1 V and the largest rectification ratio (2.7 x 10(4) at 0 V) so far reported for a green-absorbing organic photodetector. The performance of the photodetector was found to be approaching that required for current machine vision systems..