采用P3HT∶PBDT-TT-C∶PC61BM为活性层,通过溶液旋涂和高真空蒸镀工艺制备了覆盖可见光范围的高探测率有机光电探测器.利用原子力显微镜、紫外可见吸收光谱和荧光光谱研究了窄带隙聚合物红光吸收材料PBDT-TT-C掺入P3HT∶PC61BM对活性层薄膜光学特性和器件电学特性的影响.研究发现当活性层中P3HT∶PBDT-TT-C∶PC61BM质量比为8∶2∶10时,活性层的响应光谱范围拓宽到350~780 nm.其探测器在－1 V偏压下红绿蓝三基色的光响应度和外量子效率分别达到了422 mA/W、464 mA/W、286 mA/W和83%、108%、77%,比探测率均达到1012Jones以上.结果表明,在有机光电探测器活性层中掺入吸收光谱互补的有机材料,在保证薄膜微观形貌的基础上,通过调节三元混合材料的质量比,不仅可以优化载流子的产生和输运,提高器件的光电流,还可通过第三组分的掺入促进薄膜结晶,减小器件的暗电流.

A high detectivity organic photodetector with active layer P3HT:PBDT-TT-C∶PC61BM covering the visible wavelength range was prepared by solution spin coating and high vacuum evaporation. The effects of PBDT-TT-C doping P3HT∶PC61BM on the optical properties of the active layer films were investigated by atomic force microscopy, UV-visible absorption spectroscopy and fluorescence spectroscopy. It was found that when the mass ratio of P3HT∶PBDT-TT-C∶PC61BM in the active layer was 8∶2∶10, the response spectrum of the active layer was broadened to 350~780 nm. The optical responsiveness and external quantum efficiency of the red, green and blue primary colors of the detector under the bias of －1 V reached 422 mA/W, 464 mA/W, 286 mA/W and 83%, 108%, 77%, respectively, and the specific detectivity reached above 1012 Jones. The results show that the organic material with an organic material complementary is doped. On the basis of ensuring the microscopic morphology of the film, By adjusting the mass ratio of the ternary mixed material, not only the carrier generation and transport can be optimized, the photocurrent of the device is improved, but also the crystallization of the thin film can be promoted by the incorporation of the third component, and the dark current of the device can be reduced.