静电纺丝导电纳米纤维及聚合物太阳能电池溶液加工研究

发布时间：2018-03-07 23:12

本文选题：聚合物太阳能电池　切入点：溶液加工性　出处：《南昌大学》2014年博士论文　论文类型：学位论文

【摘要】：聚合物太阳能电池经过近二十年的研究，已经在活性层材料设计、活性层形貌控制、界面修饰、透明电极等领域取得了很大进展。目前光电转换效率（PCE）最高的聚合物太阳能电池已经达到商业化应用要求。除了获得更高的效率、探寻统一的器件物理解释之外，人们开始更多的关注器件性能的稳定性。聚合物太阳能电池的溶液加工与大面积低成本制备工艺兼容，成为了新的焦点问题。为此对缓冲层材料和金属电极材料的化学稳定性和溶液加工性提出了新的要求。本论文主要围绕聚合物太阳能电池组成材料的溶液加工方法进行研究，，包括活性层材料、界面层材料和金属电极材料。此外还涉及一些器件物理以及阴极缓冲层材料的探索工作。论文的内容包括： 1.实现了纯聚[2-甲氧基-5(2’-乙基)己氧基-1,4-苯撑乙烯](MEH-PPV)静电纺丝的连续制备。以氯仿/异丙醇混合溶剂进行电纺的优势在于，避免了非挥发性杂质对光电器件性能产生的负面影响。上述二元溶剂中劣溶剂异丙醇的加入增加了MEH-PPV电纺溶液的可纺性。劣溶剂的主要作用是增加分子链间相互作用、提高溶液电导率、降低溶液表面张力。对MEH-PPV溶液和薄膜紫外荧光性能的研究发现，溶剂能够显著改变MEH-PPV链间的相互作用使紫外吸收峰发生移动。纯MEH-PPV取向纤维在偏振荧光发光峰处的偏振比为5.9，各向异性值为0.47。上述数值明显高于各向同性材料，说明高分子链优先沿着电纺丝的长度方向排列。在MEH-PPV中混入聚己内酯(PCL)之后，所得混合纤维的偏振比和各向异性值分别增加到11和0.66。这是因为PCL的引入减少了MEH-PPV之间的能量传递。纯MEH-PPV电纺丝的直径在300nm至1100nm之间，将其电纺膜用作聚合物太阳能电池活性层效果不佳。原因有电纺膜厚度较厚，存在着孔隙以及相分离控制困难的问题。静电纺丝制备的共轭聚合物一维结构更适于单丝器件的制备。 2.以聚合物电纺丝作为模板，通过蒸镀金属并去除聚合物得到了可用于透明电极的金属网络。使用的聚合物有，聚乙烯基吡咯烷酮(PVP)、聚己内酯(PCL)和聚丙烯酸(PAA)。制得性能最优的Ag网络具有和ITO相当的电导性以及在300nm～1100nm范围内70%的透过率，基本满足透明电极的要求。将Ag网络用于制备P3HT：PC61BM聚合物太阳能电池，所得器件效率最高为2.0%。高于PH1000作电极的器件，低于ITO电极的器件。主要原因是Ag网络表面粗糙度较大，PH1000的厚度需要优化以降低电极的表面粗糙度，减少漏电的发生以进一步提高填充因子等性能参数。 3.将一种可溶液加工的铁电聚合物——聚偏氟乙烯六氟丙烯(P(VDF-HFP))用作聚合物太阳能电池的电极缓冲层。P(VDF-HFP)具有良好的成膜性、稳定的化学性质、广泛的商业来源并能提供可控的界面偶极。紫外光电子能谱和功函数测试表明，溶剂处理和P(VDF-HFP)都能在退火的P3HT:PC61BM表面引入附加偶极，使活性层/金属界面更有利于阴极接触。使用P(VDF-HFP)进行阴极界面修饰的效果略高于含有LiF的器件。考虑到P(VDF-HFP)能够对外界电场做出响应并改变偶极方向，我们将其用于反向器件的阳极缓冲层。所得反向器件在一开始具有很低的效率，但是随着Ag电极的氧化和P(VDF-HFP)的正极化过程，器件效率逐渐升高，最终和蒸镀MoO3的标准器件PCE相当。在稳定性上，含有P(VDF-HFP)的器件高于其他类型的器件。器件放置120天后，含有P(VDF-HFP)并经历正极化的器件PCE为2.4%，高于含有MoO3的标准器件。我们使用整体电荷转移(ICT)模型解释了偶极与表面真空能级移动、电极接触之间的关系。对P(VDF-HFP)作用的机理进行了理论解释，由此说明P(VDF-HFP)通过简单的电场极化调控能够成为通用的缓冲层材料。 4.对聚合物太阳能电池的阴极界面修饰进行了一些探索。对于反向电池的阴极修饰层ZnO，通过plasma处理能够提高器件的开路电压和填充因子，使电池PCE提高。其作用机理可能与plasma的清洁作用或新生成的含氧基团有关。将聚偏氟乙烯(PVDF)或P(VDF-HFP)旋涂在ZnO的表面能够提高器件的开路电压和稳定性。正极化过程则能使器件的开路电压进一步提高。我们还探索了一些材料用作正向电池阴极修饰层的可能性，包括富含羟基的D-甘露糖醇、富含氨基的三聚氰胺、含有羟基和羧基的D-丝氨酸、NaCl、KBr、PVDF和P(VDF-HFP)。其中甘露糖醇有阴极缓冲层的作用，但效果低于LiF。而NaCl、KBr、PVDF和P(VDF-HFP)则具有和LiF等同的效果。在阴极一侧引入Ag等离子体能使器件性能相对提高10%。
[Abstract]:Polymer solar cells after nearly twenty years of research, has been in the design of active layer material, active layer morphology control, interface modification, transparent electrodes and other fields have made great progress. At present, the photoelectric conversion efficiency (PCE) of polymer solar cells has reached the highest commercial application requirements. In addition to obtain high efficiency, explore the physical unity the explanation, people began to pay attention to the stability of device performance more. Solution processing and large area of polymer solar cell and low cost preparation process compatible, has become the focus of new problems. This puts forward new requirements on the chemical stability of buffer layer material and the metal electrode material and solution processing. To study the solution processing method this paper is mainly composed of polymer solar cell materials, including active layer material, interface layer and metal electrode materials. It has involved And some device physics and the exploration of cathode buffer layer materials. The contents of this paper include:
1. to achieve a pure poly [2- methoxy -5 (2 '- ethyl Hexyloxy) 1,4-phenylenevinylene] -1,4- (MEH-PPV) continuous preparation of electrospinning. In chloroform / isopropanol mixed solvent for electrospinning is to avoid the negative effects of non volatile impurities on the photoelectric device performance of the two. In poor solvent isopropanol solvent adding to the electrospun MEH-PPV the spinnability of the solution. The main role is to increase the poor solvent interaction between molecular chains, enhance the conductivity of solution, reducing the surface tension of solution. Research on ultraviolet fluorescence properties of MEH-PPV solution and film, solvent can significantly change the interaction between MEH-PPV chains the ultraviolet absorption peak shift. Polarization peaks of pure MEH-PPV fiber orientation in polarized fluorescence at the ratio of 5.9, the numerical value of 0.47. anisotropy was significantly higher than that of isotropic material that preferentially along the electrospinning of polymer chain The length direction. Mixed with polycaprolactone (PCL) in MEH-PPV, the mixing ratio of the fiber and the polarization anisotropy values were increased to 11 and 0.66. this is because of the introduction of PCL to reduce the MEH-PPV energy transfer. The diameter of electrospun pure MEH-PPV between 300nm and 1100nm, the electrospun membrane used polymer solar cell active layer effect. Because electrospun membrane thickness, there are pores and control of phase separation. The difficult problem of one-dimensional structure of conjugated polymer electrospun monofilament is more suitable for device fabrication.
2. by electrospinning polymer as template by metal deposition and removal of polymer obtained can be used for metal network transparent electrodes. Using polymer, polyvinylpyrrolidone (PVP), polycaprolactone (PCL) and polyacrylic acid (PAA) was prepared. The optimal performance of the Ag network and ITO has considerable electrical conductivity as well as in the 300nm ~ 1100nm range and 70% transmittance, basically meet the requirement of transparent electrodes. The Ag network is used for the preparation of P3HT:PC61BM polymer solar cells, the efficiency of the device was the highest device 2.0%. is higher than that of PH1000 electrode, ITO electrode is lower than the device. The main reason is the Ag network greater surface roughness PH1000 thickness need to be optimized to reduce the electrode surface roughness, reduce the leakage occurred in order to further improve the filling factor and other performance parameters.
3. a solution process of ferroelectric polymer - poly vinylidene fluoride hexafluoropropylene (P six (VDF-HFP)) electrode buffer layer.P as the polymer solar cell (VDF-HFP) has excellent film-forming properties, stable chemical properties, extensive commercial sources and can provide controllable interfacial dipole. Ultraviolet photoelectron spectroscopy and the work function test shows that the solvent and P (VDF-HFP) can introduce additional dipole on the surface of P3HT:PC61BM annealing, the active layer / metal interface is more conducive to the cathode contact. The use of P (VDF-HFP) cathode interfacial modification effect is slightly higher in devices with LiF. Considering the P (VDF-HFP) to the external electric field respond to and change the direction of the dipole, we will use it to reverse the anode buffer layer device. The reverse device has very low efficiency in the beginning, but with the oxidation and P Ag electrode (VDF-HFP) is the process of polarization, the device. The rate increased gradually, and the final standard device PCE MoO3 steam plating. In stability, containing P (VDF-HFP) of the device is higher than that of other types of devices. Devices placed 120 days, containing P (VDF-HFP) and positive polarization device PCE is 2.4%, higher than the standard device containing MoO3. We use the whole charge transfer (ICT) model to explain the surface dipole and the vacuum level relationship between the moving electrode contact. The P (VDF-HFP) mechanism are explained, which indicates that P (VDF-HFP) by electric field polarization can be simple regulation of buffer material universal.
The exploration of cathode interface modification of 4. polymer solar cells. The cathode reverse battery of the modified layer by ZnO, plasma treatment can improve the device open circuit voltage and the fill factor, the battery PCE increased. The mechanism may be related to oxygen containing groups cleaning effect of plasma or new generation. Polyvinylidene fluoride (PVDF) or P (VDF-HFP) surface spin coating on ZnO can improve the open circuit voltage and the stability of the device. It can make the process of polarization devices to further improve the open circuit voltage. We also explored some possibility of modification layer of cathode material used as positive cells, including hydroxyl rich D- mannose rich amino alcohol, melamine, D- serine, hydroxyl and carboxyl groups of NaCl, KBr, PVDF and P (VDF-HFP). The mannitol cathode buffer layer, but the effect is lower than that of LiF. and NaCl, KBr, PVDF and P (VDF-HFP) is The effect of LiF is equal to that of LiF. The introduction of Ag plasma on the side of the cathode can improve the performance of the device relative to 10%.

【学位授予单位】：南昌大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM914.4

【共引文献】