Performance improvement of organic bulk heterojunction solar cells by using dihydroxybenzene as additive

We report the enhanced performance of organic solar cells(OSCs) based on regioregular poly(3-hexylthiophene)(P3HT) and methanofullerene [6,6]-phenyl C61-butyric acid methyl ester(PCBM) blend by using dihydroxybenzene as additive in the active layer.The effect of the content of the additives on electrical characteristics of the device is studied.The device with 0.2 wt% dihydroxybenzene additive achieves the best power conversion efficiency(PCE) of 4.58% with Jsc of 12.5 mA/cm2,Voc of 0.65 V,and FF of 66.6% under simulated solar illumination of AM 1.5G(100 mW/cm2),compared with the control device with PCE of 3.39%(35% improvement compared with the control device).The XRD measurement reveals that the addition of additives induces the crystallization of P3HT and establishes good inter-network to increase the contact area of donor and acceptor,and then helps charge to be effectively transferred to the electrode to reduce the chance of recombination.All evidences indicate that the dihydroxybenzene is likely to be a promising new type additive that can enhance the performance of organic bulk heterojunction solar cells.     

以Zn(BTZ)_2∶rubrene为发光层的一种新型白色有机电致发光液晶显示背光源

制备了以Zn(BTZ)2∶rubrene为发光层的5种白色有机电致发光器件,并将其应用于液晶显示背光源。5种器件色度最好时的CIE坐标值为(0.32,0.33),最大有效发光面积达到3 cm×3 cm,此时器件的平均亮度达到264 cd/m2,亮度均匀性达到80%。并且分析了随器件有效发光面积增大,发光均匀性、亮度以及最大量子效率减小而器件电流密度反而增大的原因。同时发现附加金属(Ag)辅助电极在一定程度上有助于提高器件的性能。最后将所制备的5种器件与液晶显示屏相匹配,它们均基本满足液晶显示对背光源的要求。     

掺杂TBPe的单一发光层白色OLEDs研究

以聚合物poly（N-vinylcarbazole）（PVK）为主体材料，分别掺入蓝光染料2，5，8，11-tetra-tertbutylperylene（TBPe）和橙黄光染料5，6，11，12-tetraphenyl-naphthacene（Rubrebe），制成单层白色有机电致发光器件（WOLED）。通过多组实验结果的对比，最终确定了最佳染料掺杂浓度和器件结构，得到最佳色举标为（0．33，0．38），已位于该坐标的白色等能区之内，且随着外加电压由8V增加到16V，色坐标保持不变。器件的亮度为553cd／m^2，外量子效率为0．16％。     

用于液晶背光源的双层掺杂白光OLED

制备了一种双层掺杂的白光有机电致发光器件(OLED),其中BAlq:TBPe掺杂层发蓝光,Zn(BTZ)2:Rubrene掺杂层发橙色光.器件在驱动电压5 V时就能发出白光,且在驱动电压5～15 V内色坐标变化较小,均在白光色域区,在15 V时亮度达到8 572 cd/m2,在电流密度50 mA/cm2时量子效率最高达到0.9%.对该白光OLED的发光和电学性能以及发光机理进行了深入的研究和探讨,进而制备了应用于液晶显示(LCD)背光源的近白光OLED,有效面积达到3 cm×3 cm,在10 V时平均亮度达到～1 300 cd/m2,发光亮度均匀性为90%,色度均匀性较好,很好地符合了LCD对背光源的要求.     

以Zn(BTZ)2:rubrene为发光层的一种新型白色有机电致发光液晶显示背光源

制备了以Zn(BTZ)2 rubrene为发光层的5种白色有机电致发光器件,并将其应用于液晶显示背光源.5种器件色度最好时的CIE坐标值为(0.32,0.33),最大有效发光面积达到3 cm×3 cm,此时器件的平均亮度达到264 cd/m2,亮度均匀性达到80 %.并且分析了随器件有效发光面积增大,发光均匀性、亮度以及最大量子效率减小而器件电流密度反而增大的原因.同时发现附加金属(Ag)辅助电极在一定程度上有助于提高器件的性能.最后将所制备的5种器件与液晶显示屏相匹配,它们均基本满足液晶显示对背光源的要求.     

单层结构白色聚合物电致发光器件制备及其性能

选择梯形对次苯基聚合物(I．PPP)为母体和蓝色发光材料,掺杂MEH-PPV、OXD-7、PMMA分别作为橙红色发光材料、电子传输材料和绝缘介质材料,用旋涂法制成结构为ITO／白色发光层／A1的单层白色有机发光器件。对器件进行热处理(最佳热处理条件为180℃,1h)后,发现器件的发光性能得到明显改善。驱动电压25V时器件的发光亮度由42cd／m^2提高到355cd／m^2,色坐标为(x=0．332,y=0．347),非常接近于白色等能点。     

Reusing of transmitted light by localized surface plasmon enhancing of Ag nanoparticles in organic solar cells

Silver nanoparticles(Ag NPs)are synthesized with chemical method,which are introduced into the traditional organic photovoltaic(OPV)structure.The experimental results show that both the optical and photoelectric properties are en-hanced because of localized surface plasmon(LSP)effects of Ag NPs.The advantage of adding Ag NPs behind active layer in incident direction is discussed.We believe this route can avoid absorption shadow and enhance the reusing of transmitted light of active layer.The average short-circuit current(J SC)of the optimum device can be raised from 9.23mA/cm2 to 10.84mA/cm2,and the energy converting efficiency(PCE)can be raised from 3.22% to 3.85%.     

An air-stable inverted photovoltaic device using ZnO as the electron selective layer and MoO3 as the blocking layer

An air-stable photovoltaic device based on znic oxide nanoparticles (ZNP) in an inverted structure of indium tin oxide (ITO)/ZnO/poly (3-hexylthiophene) (P3HT): [6,6]-phenyl C61-butyric acid methyl ester (PCBM)/MoO3/Ag is studied. We find that the optimum thickness of the MoO3 layer is 2 nm. When the MoO3 blocking layer is introduced, the fill factor of the devices is increased from 29% to 40%, the power conversion efficiency is directly promoted from 0.35% to 1.27%.The stability under ambient conditions of this inverted structure device much is better due to the improved stability at the polymer/Ag interface. The enhancement is attributed to the high carriers mobility and suitable band gap of MoO3 layer.     

低温处理的TiO2纳米颗粒薄膜作为缓冲层的有机光伏电池

通过溶胶凝胶法(sol-gel)合成了TiO₂纳米颗 粒(NPs),制备了结构为 ITO/PEDOT:PSS/P3HT:PCBM/TiO₂/Al的有机太阳能电池(OSC)器件。通过优化阴极缓冲 层TiO₂NPs的 热处理温度,考察了温度以及溶剂对TiO₂NPs薄膜的光学性能、形貌结构和电学 性能的影响,并研究了其对OSC性能的影响及作用机理。实验发现,TiO₂NPs处理温度 为80℃时,器件 的效率达到了2.52%。相对于参比器件,器件的光电转换效率(PCE) 、填充因子(FF)分别提高了60%、64.7%。     

双发光层白色FOLED的制备及其性能研究

采用以含ITO导电层的柔性透明PET基片作为衬底,荧光材料TBPe、Rubrene分别掺杂在主体材料CBP和Balq中作为蓝色发光层和橙红色发光层,制备了双发光层白色柔性有机电致发光器件(FOLED)。通过适当调节发光层的掺杂比例和厚度,得到了发光性能理想的白光器件。测量表明,制备的器件色稳定性很好,色度随外加驱动电压在很大范围内变化很小,且其色坐标均非常接近于白色等能点。当电流密度为50mA/cm2时,器件最高外量子效率达到0.9%。通过抗弯折性能的测试证明,可以基本实现柔性显示的目的。