【作者】 曹雷；

【导师】 汪茫； 陈红征；

【作者基本信息】 浙江大学 ， 高分子化学与物理， 2004， 博士

【摘要】 本文综述了纳米碳管／有机（聚合物）半导体复合光电功能材料的制备与应用的研究进展，并介绍了基于纳米碳管的复合材料在红外探测领域的应用。光致电荷转移可显著提高载流子的解离、传输效率，是优化光电功能器件性能的有效途径。通过分子设计和复合材料凝聚态结构的剪裁、调控可显著提高光致电荷转移效率。本论文以共混掺杂、毛细管浸润填充、相分离模板自组装和电泳沉积法制备了纳米碳管／稀土酞菁有序复合材料，并研究了其光电性能。 通过化学修饰制备了接枝十二胺的纳米碳管，其在溶液中的分散性和与聚合物的相容性有了明显改善。制备了酞菁氧钛／纳米碳管复合光电导材料，并以其为载流子产生层制备双层感光体，通过光致放电法研究了其光电导性能，复合材料的光敏性在全波长范围内比单一的酞菁氧钛有了很大提高，当掺杂纳米碳管重量比达到6％时，复合材料的光敏性达到最佳，在570nm处(E_1/2)^-1达到10μJ^-1cm²，比纯酞菁氧钛提高了5倍。XPS光电子能谱测试表明，掺杂纳米碳管后酞菁氧钛发生了由苯环向中心氧原子的分子内电荷转移，钛菁氧钛更易被激发形成电荷转移激子，这是光电导性能提高的主要原因。由酞菁氧钛到纳米碳管的分子间光致电荷转移作用提高了酞菁氧钛光生载流子的解离效率，是光电导性能优化的另一原因。 具有大面积界面、分子级紧密接触的电子给体—受体复合体系有利于光致电荷转移作用的发生，从而提高复合材料的光电性能。以毛细管浸润填充法制备了酞菁铒／纳米碳管一维复合物，通过调节溶液浓度、浸润时间和纳米碳管管径可以使酞菁铒以纳米晶、纳米棒和纳米线填充在纳米碳管中。这类一维复合材料在近红外区有良好的光敏性。以纳米碳管为模板通过相分离法制备了具有核／壳结构的纳米碳管／酞菁铒杂化纳米线。通过调节酞菁铒浓度可制备以纳米碳管为模板的酞菁铒的纳米晶和纳米线。以核／壳纳米线为载流子产生材料制备了双层感光体，其光电导性能比纯酞菁铒有了很大提高，在762.5nm处(E_1/2)^-1达到0.833μJ^-1cm²，为酞菁铒的4倍多。UV-Vis吸收光谱表明酞菁铒与纳米碳管间形成了电荷转移络合物，激发态时两者间的光致电荷转移是光电导性能优浙王〔大学博d匕学位论文摘要化的主要原因。 通过真空蒸镀制备了酞著礼和酞著饵薄膜，研究了基片温度、沉积时间对薄膜形貌、晶体结构和光谱响应的影响。低基片温度制备的酞著礼和酞著饵薄膜呈球形颗粒状晶体，结晶度较低;随着基片温度升高，晶体尺寸和结晶度增大，当基片温度100oC时，酞著礼和酞菩饵呈纺锤状晶体，并有较高的结晶度，晶体平行于基片方向取向。真空蒸镀制备的酞著礼和酞菩饵薄膜在可见光和近红外区都有较高光敏性，表明稀土酞著可用于制备薄膜型红外探测器。 稀土酞著在酸性溶液中易被质子化，质子化的分子在外加电场作用下可定向迁移，以电泳沉积法在导电玻璃和硅片上制备了酞著扎薄膜，研究发现通过调节沉积时间、电场强度和溶液浓度可调控酞蓄礼薄膜的聚集态结构。随着沉积时间的延长，可使酞著礼以纳米晶、纳米线、微米棒和微米线沉积在基片上;通过调节电场强度，可实现对纳米线和微米线取向的调控，还可以制备Y型分叉结构的微米线。研究了施加外场一磁场时酞著礼的电化学沉积行为，发现当磁场方向平行于基片时有利于形成酞著礼的微米线阵列。通过紫外一可见光一近红外吸收光谱研究了酞著礼薄膜的光响应性。以X射线衍射表征了薄膜的晶态结构。通过真空蒸镀在酞著礼薄膜上沉积了N型有机半导体花四酸配，制备了P一N结有机太阳能电池，研究了其光伏特性，酞著礼微米线阵列垂直于基片时器件表现出比微米线平行于基片时更大的光电流，载流子的传输通道和传输方向一致是器件性能优化的主要原因。研究了酞普礼薄膜的电致变色性质，H聚体一J聚体的转变是产生这一现象的原因。以电泳沉积制备了纳米碳管薄膜，以溶液浸涂法制备了纳米碳管/酞著礼复合膜。复合膜中酞著扎自组装为纳米棒，垂直于基片取向，与纳米碳管形成了连续互穿网络复合结构，这一复合膜具有较强的近红外光响应性。 本论文研究了纳米碳管/有机半导体复合材料的制备及其光电性能，对于制备基于纳米碳管/有机半导体复合材料的光电子器件有一定的理论意义。更多还原

【Abstract】 The recent progresses in preparation and applications of carbon nanotube (CNT)/organic semiconductor hybrids were summarized in Chapter 1. The potential application of the hybrids in the near-infrared (NIR) detection was introduced. The performance of optoelectronic devices depends heavily on their excited state property, which mainly involves charge carrier generation, separation, and transportation. The optimal performance can be obtained via designing of molecular structure and modulating of aggregated structure. In this dissertation, three approaches, from blend, encapsulation and enrobe, to electrochemical deposition, were carried out to fabricate high photosensitive CNT/phthalocyanine hybrids in the light of molecular and material designs. The optoelcteronic property of the hybrids was investigated in detail as well.The multi-wall carbon nanotubes (MWCNT) bonded with dodecylamine groups were obtained by chemical modification. The modified CNT showed improved solubility in organic solvents and miscibility with polymer matrix. The photoconductivity of oxotitanium phthalocyanine (TiOPc) doped with modified CNT was investigated by the xerographic photoinduced discharge method. The results showed that the photosensitivity of the dual-layer photoreceptor (P/R) with modified CNT/TiOPc composite as charge generation material was higher than that with pristine TiOPc, and increased with increasing the content of modified CNT in the composites. The optimal performance was obtained when the weight ratio of doped CNT was 6% and a high (E1/2)-1 of 10 J-1cm2 was obtained at 570 nm, nearly 5 times higher than that of pristine TiOPc at the same wavelength. It was explained that, as demonstrated by XPS, after doping with modified CNT, the intramolecular charge transfer occurred in TiOPc and the charge transfer exciton was prone to be produced, which was favorable to charge carrier generation. The efficiency of charge carrier separation increased as well due to the photoinduced charge transfer from TiOPc to CNT, which might also contribute to the improved photosensitivity of the modified CNT/TiOPc composites.To facilitate the photoinduced charge transfer, the fabrication of one-dimensional (1 D) CNT/rare earth biphthalocyanine hybrid materials with large interfacial area wasexploit. The erbium biphthalocyanine (ErPc2) nanorods or nanowires were encapsulated in the cavities of CNT by a capillary filling method. The length and the diameter of the ErPci nanowires can be easily tailored by the CNT mold, capillary filling time, and the concentration of ErPc2. The CNT/ErPc2 hybrid materials exhibit photoresponse at the NIR region. CNT templated assembly of ErPc2 nanowires was performed by the phase separation (coacervation) method. The length and the diameter of the nanowires can be easily tailored by the nanotube template and the concentration of ErPc2. The photoconductivity of the CNT wrapped with ErPc2 nanowires was investigated. The dual-layer photoreceptors with CNT/ErPc2 hybrid materials as charge generation materials exhibited enhanced photosensitivity compared to that with pristine ErPc2. At 762.5 nm, a high (E1/2)-1 of 0.833 J-1cm2 was obtained, more than 4 times higher than that of pristine ErPc2. The improved photosensitivity was contributed from the photoinduced charge transfer from ErPc2 to CNT. Combining the optic, electronic, and magnetic properties of rare earth phthalocyanines and CNT, the 1 D hybrid materials are expected to have versatile potential applications in optoelectronic devices.Gadolinium biphthalocyanine (GdPc2) and ErPc2 thin films were prepared by vacuum deposition at various substrate temperatures. The effects of substrate temperature and film thickness on the film morphology, crystalline structure, and optical absorption were studied. The ErPc2 and GdPc2 films exhibited fine-grain morphology and small degree of crystallization at low substrate temperature. The size of the crystallites was enlarged when the film thickness increases. If the substrate temperature was elevated to 100, the ErPc2更多还原