A Simple Interconnection Layer for Tandem Organic Solar Cells with Improved Efficiency and Fill Factor

We demonstrate a simple interconnection layer （ICL） that can be employed in tandem organic solar cells. An ICL with an optimized structure of Ca/Au/MoO3 is used between two sub cells composed of identical regioregularpoly（3-hexylthiophen） （P3HT）：[6,6]-phenyl C61-butyric acid methylester （PCBM） photoactive layers. Power conversion efficiency （PCE） of 3.24% and fill factor （FF） of 68.0% are achieved with such an ICL under simulated sunlight （1 O0 m W. cm- 2 ）. Compared with the best values of devices with ICLs of Ca/Al/MoOa, PCE is improved by 68.9% and FF is improved by 15.5%. The improved performances are attributed to the optical and electrical balances in both sub cells. The presented ICL extracts free charges efficiently from both sub cells thereby suppressing the exaction recombination in each sub cell.     

基于含芴菲并咪唑衍生物的可湿法加工的蓝光有机电致发光器件

设计合成了一种新型A-D-A含芴菲并咪唑和炔基基团的蓝光分子( FI),采用紫外吸收、光致发光光谱和循环伏安对材料进行了表征,发现该物质具有稳定的蓝光发射。采用旋涂的方法制备了非掺杂蓝光有机发光二极管,器件的最大电流效率为1.52 cd·A-1,最大功率效率为0.63 lm·W-1.     

高效钙钛矿-有机本体异质结杂化串联太阳能电池

制备了一种有机铅卤钙钛矿-有机本体异质结杂化串联太阳能电池。采用紫外可见吸收光谱、原子力显微镜对薄膜形貌进行了表征。结果表明:有机本体异质结层可以有效改善钙钛矿的表面形貌, 增强了可见光的吸收。优化后的串联结构电池的短路电流可达19.14mA/cm², 开路电压为0.76V, 光电转换效率达到了6.54%。钙钛矿电池和有机本体异质结电池串联结构可以同时提高短路电流及填充因子, 二者具有较好的相容性和协同作用。     

在电子传输层中添加PVK提高钙钛矿太阳能电池的性能

为了探究PVK对倒置平面异质结钙钛矿太阳能电池电子传输层的影响,向电子传输层PCBM中添加了一种富电子的聚乙烯基咔唑(PVK).采用原子力显微镜、PL光谱对薄膜进行了表征.实验结果表明:少量PVK的添加提高了覆盖在钙钛矿薄膜上PCBM层的平整度.当PVK的添加质量分数为4%时得到最佳器件效率,相比于纯PCBM作为电子传输层的器件,器件效率由(5.11±0.14)% 提升到(9.08±0.46)%.当PVK的添加质量分数大于4%时,粗糙度又趋于变大.PL光谱显示,少量PVK的加入使钙钛矿/电子传输层薄膜的PL强度降低,并使PL峰蓝移.研究表明:向PCBM中掺杂适量PVK能够改善钙钛矿/电子传输层/Al的界面接触,减少漏电流,并能够减少钙钛矿表面陷阱和晶界缺陷,减少电荷复合,从而提高了器件性能.     

Lowering the driving voltage and improving the luminance of blue fluorescent organic light-emitting devices by thermal annealing a hole injection layer of pentacene

We chose pentacene as a hole injection layer (HIL) to fabricate the high performance blue fluorescent organic light-emitting devices (OLEDs). We found that the carrier mobility of the pentacene thin films could be efficiently improved after a critical annealing at temperature 120 °C. Then we performed the tests of scanning electron microscopy, atomic force microscopy, and Kelvin probe to explore the effect of annealing on the pentacene films. The pentacene film exhibited a more crystalline form with better continuities and smoothness after annealing. The optimal device with 120 ℃ annealed pentacene film and n-doped electron transport layer (ETL) presents a low turn-on voltage of 2.6 V and a highest luminance of 134800 cd/m² at 12 V, which are reduced by 26% and improved by 50% compared with those of the control device.     

Improved performance of organic light-emitting diodes with dual electron transporting layers

In this study the performance of organic light-emitting diodes(OLEDs) are enhanced significantly,which is based on dual electron transporting layers(Bphen/CuPc).By adjusting the thicknesses of Bphen and CuPc,the maximal luminescence,the maximal current efficiency,and the maximal power efficiency of the device reach 17570 cd/m2 at 11 V,and 5.39 cd/A and 3.39 lm/W at 3.37 mA/cm2 respectively,which are enhanced approximately by 33.4%,39.3%,and 68.9%,respectively,compared with those of the device using Bphen only for an electron transporting layer.These results may provide some valuable references for improving the electron injection and the transportation of OLED.     

Improved Performance of Phthalocyanine Derivative Field-Effect Transistors by Inserting a Para-Quarterphenyl as the Inducing Layer

We investigate the phthalocyanine derivative organic field-effect transistors （OFETs） using a novel para - quaterphenyl （p-4p） as the inducing layer. Compared to the devices without the p-4p inducing layer, the performances of p-type （copper phthalocyanine） and n-type （fluorinated copper phthaloeyanine） OFETs with optimized thickness of p-4p thin films are greatly enhanced. Both the field-effect mobility and the on/off ratio of the two-type devices are improved by one order of magnitude compared to those of the control devices. This re- markable improvement is attributed to the introduction of p-4p, which can form a highly oriented and continuous phthalocyanine derivative film with the molecular π - π stack direction parallel to the substrate.     

Effect of NaCl doped into Bphen layer on the performance of tandem organic light-emitting diodes

To improve the performance of tandem organic light-emitting diodes （OLEDs）, we study the novel NaCl as n-type dopant in Bphen：NaCl layer. By analyzing their relevant energy levels and cartier transporting characteristics, we discuss the mechanisms of the effective charge generation layer （CGL） of Bphen：NaCl （6 wt%）/MoO3. In addition, we use the Bphen：NaC1 （20 wt%） layer as the electron injection layer （ELL） combining the CGL to further improve the performance of tandem device. For this tandem device, the maximal current efficiency of 9.32 cd/A and the maximal power efficiency of 1.93 lm/W are obtained, which are enhanced approximately by 2.1 and 1.1 times compared with those of the single- emissive-unit device respectively. We attribute this improvement to the increase of electron injection ability by introducing of Bphen：NaCl layer. Moreover, the CGL is almost completely transparent in the visible light region, which is also important to achieve an efficient tandem OLEDs.     

Zn(BTZ)2白色有机电致发光材料的合成及其器件制备

以PCl₃为脱水剂,将邻氨基硫酚与水杨酸脱水环化合成出2-(2-羟基苯基)苯并噻唑,并进一步将所得产物与乙酸锌反应合成出2-(2-羟基苯基)苯并噻唑螯合锌(Zn(BTZ)₂)材料。以该配合物作为发光层制备出结构为ITO/PVK:TPD/Zn(BTZ)₂/Al近白色电致发光器件,其色坐标位于白场之内(x=0.242,y=0.359),在驱动电压为16V时,亮度达3200cdm²,对应的量子效率为0.32%。进一步在Zn(BTZ)₂中掺入橙红色染料Rubrene,制成ITO/PVK:TPD/Zn(BTZ)₂:Rubrene/Al结构器件,实现了纯白色发光(色坐标值:x=0.324,y=0.343),非常接近于白色等能点,且量子效率达0.47%。最后对上述器件的发光和电学性能进行了深入的研究和探讨。     

含吩噻嗪及其衍生物的聚合物有机电致发光材料的合成和器件制备

利用吩噻嗪单体的空穴传输能力、吩噻嗪衍生物单体的拉电子特性和它们分子结构的非共面性,制备了高效的含吩噻嗪及其衍生物结构单元的对苯撑乙烯聚合物有机电致发光材料P1。同时在单体中引入了烷氧基和长链烷基,使得合成的聚合物在四氢呋喃、氯仿、二氯甲烷、甲苯等溶剂中有较好的溶解性。研究吩噻嗪衍生物单体的拉电子特性对聚合物P1的电子传输性能的影响,合成不含吩噻嗪衍生物的同一类型聚合物P2。制备以聚合物P1和P2为发光层的单层OLED器件,经测量,聚合物P1的器件外量子效率是聚合物P2器件的3.5倍。