【作者】 李海国； 吴刚； 陈红征； 汪茫；

【Author】 Li Haiguo Wu Gang Chen Hongzheng Wang mang (Department of Polymer Science and Engineering;Key Laboratory of Macromolecule Synthesis and Functionalization,Ministry of Education;State Key Lab of Silicon Materials,Zhejiang University,Hangzhou 310027,China)

【机构】 浙江大学高分子科学与工程学系,高分子合成与功能构造教育部重点实验室,硅材料国家重点实验室；

【摘要】 以聚(9,9-二己基芴)(PFH)为电子给体材料,湿法ZnO纳米晶为电子受体材料,通过溶液旋涂法制备了有机/无机杂化紫外探测器。采用的器件结构包括本体异质结(BHJ)和平面异质结(PHJ)构型。BHJ器件活性层为给、受体材料的共混薄膜,器件性能可通过活性层中ZnO的含量来调控。当ZnO含量为50%(重量比,相对PFH)时,器件在1mW/cm2365nm紫外光照,-1V偏压下,响应率为94mA/W,光暗电流比为3个数量级,且器件在空气中经过充分陈化后可实现快速响应。PHJ器件是通过逐层旋涂的方法制备的,根据给、受体层沉积次序的不同,分为反向器件(IPHJ:ITO/ZnO/PFH/Au)和正向器件(NPHJ:ITO/PFH/ZnO/Al)。当1mW/cm2365nm紫外光从ITO侧入射时,两种器件均呈现出明显的光电响应,光暗电流比可以达到3～4个数量级。在负偏压下,IPHJ器件的光电响应呈现出明显的持续光电导现象,而对于NPHJ器件,在光照去除后,由于氧气能及时俘获ZnO中的自由电子,其电流可以迅速回复。更多还原

【Abstract】 Hybrid ultraviolet photodetectors have been demonstrated by spin-coating using poly(9,9-dihexylfluorene-2,7-diyl) (PFH) and ZnO nanocrystals as electron donor and acceptor,respectively.Both bulk heterojunction (BHJ) and planar heterojunction (PHJ) devices are fabricated.For BHJ devices,a PFH:ZnO blend layer is applied and the performance can be tuned by the amount of ZnO introduced in the polymer.When blend with 50% (by weight,relative to PFH) ZnO is used,the device exhibits a responsivity of 94 mA/W at-1V under illumination of 1 mW/cm 2 365 nm UV light.A photo-to-dark current ratio of 3 orders of magnitude can be obtained and rapid response can be realized after aging in air for enough time.For PHJ device,layer-by-layer structure is applied.According to the deposition order of the donor and acceptor layers,the devices can be divided into inverted device (IPHJ:ITO/ZnO/PFH/Au) and normal device (NPHJ:ITO/PFH/ZnO/Al).Both devices exhibit obvious photoresponse with photo-to-dark current ratio of 3～4 orders of magnitude under illumination of 1 mW/cm 2 UV light at 365 nm through the ITO electrode.Under reverse bias,the photoresponse of IPHJ device exhibits severe persistent photoconduction.However,this is efficiently avoided in NPHJ device due to the presence of sufficient oxygen to capture the free electrons in ZnO.The study shown here may provide a useful guideline to achieve low-cost hybrid UV detectors with rapid response.更多还原