具有D-π-A结构的蓝色发光材料的制备及性能研究
发布时间：2018-10-08 15:01
【摘要】：有机电致发光器件(OLED)与其他显示相比具有主动发光、低驱动电压、全视角、响应快、工作温度范围宽、可柔性显示等优点被认为是下一代显示技术的主流。在OLED全彩显示和固态照明领域,特别是白色OLED,需要通过红、绿、蓝三基色或者蓝与橙两种颜色组成。但是蓝光发射需要较高的激发能,引起能量转移,从而引起色度不足。因此高效蓝色发光材料是限制蓝光OLED的瓶颈,这就要求对蓝光荧光材料的设计和合成有一定的策略。本文围绕芴基团、蒽基团为中心核设计和制备了蓝光材料。本论文的主要工作如下:(1)设计和制备了A-D-A结构,由炔基相连芴的菲并咪唑化合物FI,作为无掺杂的蓝光OLED的发光层。该化合物在244℃出现吸热熔融峰,其Td为426℃,表明具有良好的热稳定性。UV-vis计算得到FI的带隙大于3.0 e V,符合蓝光材料对宽带隙的要求。理论计算发现该分子呈现扭曲空间结构,能够很好的抑制分子在薄膜中相互作用,抑制其激基复合物或激基缔合物的形成。最后以FI为发光层通过湿法加工制备了非掺杂的单层OLED。通过添加TPBi,器件的最大CE为3.0 cd?A-1,最大PE为1.7 lm?W-1。本分子设计策略为可湿法加工的以芴基团为基础的蓝光OLED提供了一种新的合成理念。(2)设计合成了以蒽为核的含三苯胺基团的蓝光发光材料DTPAAN和DTPABAN。通过TG、UV-vis和PL分析了材料的热稳定性及光学性能。化合物DTPAAN和DTPABAN,Td分别为378℃、390℃,具有良好的热稳定性。通过UV-vis计算,发现DTPAAN与DTPABAN的带隙都大于3.0 e V,满足蓝光材料对宽带隙的要求。将中心核由蒽换为联蒽,发现在固态状态下荧光发射峰没有明显的偏移,这可能是分子内电荷转移态的扭曲构型导致了低荧光过渡态。因为两个蒽的二面角的角度会随着分子偶极矩的改变而不同。理论计算发现分子呈现扭曲空间结构,能够很好的抑制分子在薄膜中相互作用,进而抑制其激基复合物或激基缔合物的形成。因此,DTPAAN和DTPABAN应属于蓝光发光材料。(3)设计并合成了含有螺二芴、蒽和三苯胺基团的分子结构为D-A-D-A-D的新型蓝色荧光材料DTPAAN-SF。该化合物Td为505℃,具有良好的热稳定性。通过UV-vis计算,发现DTPAAN-SF的带隙大于3.0 e V,满足蓝光材料对宽带隙的要求。薄膜的PL峰为474 nm,其EL谱应该与其相一致。因此,DTPAAN-SF应属于蓝光发光材料。
[Abstract]:Compared with other displays, organic electroluminescent devices (OLED) have the advantages of active luminescence, low driving voltage, full angle of view, fast response, wide range of operating temperature, flexible display and so on, which are considered to be the mainstream of the next generation display technology. In the field of OLED full color display and solid state lighting, white OLED, is made up of red, green and blue primary colors or blue and orange colors. However, blue emission requires high excitation energy, which leads to energy transfer, which leads to chroma deficiency. Therefore, high efficient blue luminescent materials are the bottleneck of limiting blue OLED, which requires a certain strategy for the design and synthesis of blue fluorescent materials. Blue light materials were designed and prepared around fluorene group with anthracene group as the core. The main work of this thesis is as follows: (1) the structure of A-D-A was designed and prepared, and FI, a benzyl linked fluorene compound, was used as the luminescent layer of undoped blue-light OLED. The endothermic melting peak of the compound appeared at 244 鈩，
本文编号：2257203
[Abstract]:Compared with other displays, organic electroluminescent devices (OLED) have the advantages of active luminescence, low driving voltage, full angle of view, fast response, wide range of operating temperature, flexible display and so on, which are considered to be the mainstream of the next generation display technology. In the field of OLED full color display and solid state lighting, white OLED, is made up of red, green and blue primary colors or blue and orange colors. However, blue emission requires high excitation energy, which leads to energy transfer, which leads to chroma deficiency. Therefore, high efficient blue luminescent materials are the bottleneck of limiting blue OLED, which requires a certain strategy for the design and synthesis of blue fluorescent materials. Blue light materials were designed and prepared around fluorene group with anthracene group as the core. The main work of this thesis is as follows: (1) the structure of A-D-A was designed and prepared, and FI, a benzyl linked fluorene compound, was used as the luminescent layer of undoped blue-light OLED. The endothermic melting peak of the compound appeared at 244 鈩，
本文编号：2257203
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