摘要
利用基于萘[1,2-c:5,6-c]二[1,2,5]噻二唑共轭聚合物(NTOD)为给体,富勒烯衍生物PC71BM为受体,制备本体异质结聚合物光探测器.NTOD与PC71BM的共混薄膜吸收范围为300~830 nm.通过对NTOD:PC71BM活性层厚度的调控实现器件暗电流密度的显著降低,增强了探测器的二极管性能,同时保持较高的外量子转化效率.当活性层厚度为385 nm时,聚合物光探测器在-0.1 V偏压下的暗电流为6.69×10–10A cm^(-2).在–0.1 V偏压下器件在440~800 nm的工作波段的比探测率均超过1013 cm Hz^(1/2)W^(-1),处于750 nm的工作波长下达到最大比探测率为1.50×1013 cm Hz^(1/2) W^(-1),光响应率为0.22 A W^(-1),这些结果表明基于NTOD:PC71BM的有机光探测器具有广阔的应用前景.
Naphtho[1,2-c：5,6-c＇]bis（[1,2,5]thiadiazole）（NT） unit with centro-symmetric and enlarged planar π-conjugated structure is one of the most promising electron-withdrawing moieties for the construction of highperformance conjugated polymers for solar cells and organic field-effect transistors.Recently,an NT based narrowbandgap conjugated polymer（NTOD）,consisting of NT as the electron-withdrawing unit and 2,5-bis（3-alkylthiophen-2-yl）thieno[3,2-b]thiophene as the electron-donating unit,has been developed,which exhibited a remarkable power conversion efficiency exceeding 10% and might be used to construct device with thick active layer over 300 nm.Considering the impressive photovoltaic performances achieved based on the NT-polymers,here we designed and fabricated solution-processed polymer photodetectors using NTOD as the electron donor.Device with architecture of ITO/PEDOT：PSS/active layer/Al was fabricated to investigate the performance of the photodetector.The active layer was comprised of NTOD as the electron donor and a fullerene derivative of（6,6）-phenyl-C71-butyric acid methyl ester（PC71BM） as the electron acceptor,which displayed broad absorption spectra ranging from 400 nm to 830 nm.We noted that the dark current density of the photodetectors was effectively suppressed by increasing the thickness of the NTOD：PC71BM based active layer,while the external quantum efficiency（EQE） of the devices maintained relatively high.It is also worth pointing out that,when the thickness of the active layer increased up to 385 nm,the device exhibited low dark current density of 6.69 × 10^–10 A cm^–2 at –0.1 V,for which the specific detectivity（D＊） is higher than 10（13） cm Hz^1/2 W^-1 in the range of 440 – 800 nm,with champion detectivity of 1.50 × 10^13 cm Hz^1/2 W^-1 and responsivity of 0.22 A W^–1 at 750 nm.Moreover,the polymer photodetector exhibited a high detectivity of 1.10 × 10^13 cm Hz^1/2 W^-1 at 800 nm,suggesting the good detectivity extending to near-infrared（NIR） region.These results indicate that the NTOD polymer has great potential for the construction of high performance polymer photodetectors.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2018年第2期217-222,共6页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号51673069
21634004
91633301
21520102006)
广州市科技计划(项目号201707020019)资助
关键词
萘二并噻二唑
共轭聚合物
窄带系
光探测器
Naphtho[ 1,2-c：5,6-c＇]bis（[ 1,2,5]thiadiazole）, Conjugated polymers, Narrow bandgap, Polymer photodetector
