退火方式及PCBM阴极修饰层对聚合物太阳电池的影响

研究了不同退火方式及PCBM阴极修饰层对聚合物太阳电池性能的影响。与前退火相比,后退火的器件性能显著提高,电池的开路电压Voc由0.36V增加到0.60V,能量转换效率η从0.85%提高到1.93%,短路电流密度Jsc和填充因子FF也有不同程度的改善;在电池的活性层与Al电极间沉积一定厚度的PCBM阴极修饰层也能改善电池的性能,当PCBM厚度为3nm时,聚合物太阳电池在100mW.cm-2强度光照下,Voc为0.59V,Jsc为6.43mA.cm-2,FF为55.1%,η为2.09%。     

量子点在聚合物太阳电池中的应用

介绍了聚合物太阳电池的一般原理、性能表征,以及聚合物/量子点太阳电池结构,重点列举了有机及无机量子点在聚合物太阳电池中的应用,最后提出了改善聚合物/量子点太阳电池效率的方法。     

超薄PCBM层提高有机太阳电池效率

为研究超薄PCBM层对有机太阳电池的影响,制备了含和不含超薄PCBM层的两种不同结构的体相异质结太阳电池,电池结构分别为:ITO/PEDOT:PSS/P3HT+PCBM/PCBM/AI,ITO/PEDOT:PSS/P3HT+PCBM/Al.测试结果表明:所制备电池的开路电压分别为0.599 2V和0.572 7 V,能量转换效率分别为2.24％、1.21％,超薄PCBM层起到了电子传输的作用.     

金属表面等离激元增强聚合物太阳电池

研究了Au纳米颗粒表面等离激元增强聚噻吩(P3HT)与富勒烯衍生物(PCBM)共混体系聚合物太阳电池的光电转换效率。Au纳米颗粒表面由双十烷基二甲基溴化铵(DDAB)修饰,能够均匀分散在活性层中。研究了Au纳米颗粒的质量分数对电池性能的影响,发现质量分数为1.2%时,电池性能最佳,转换效率高达3.76%,较未掺杂的参比电池相对提高约20%。掺入Au纳米颗粒后P3HT和PCBM共混膜光吸收显著增强,从而使电池外量子效率大大增加。电池效率的提升主要归结于Au纳米颗粒表面等离激元激发所引起的近场增强。     

NPB修饰层提升聚合物太阳电池的性能

将广泛用于光伏器件的有机材料二胺(NPB)应用到光电器件中,是一种新的提升器件性能的思路。基于NPB材料的空穴传输特性,以3-己基噻吩的聚合物(P3HT)和富勒烯衍生物(PCBM)作为活性层,制备了不同阳极修饰层的太阳电池,研究了NPB修饰层对器件性能的影响。通过光照和黑暗条件下电学特性的比较以及拟合计算,分析了NPB修饰层对性能影响的内在原因,并对其厚度做了优化。结果表明:NPB厚度为5 nm时,器件的短路电流、开路电压和填充因子都有所提高。NPB修饰层可以改善界面接触,提高空穴的收集效率。     

非晶硅太阳电池的衰减与退火

讨论了影响非晶硅太阳电池稳定性的因素,介绍了改善非晶硅材料稳定性的方法,进行了非晶硅太阳电池光致衰减测试.描述了电流注入退火和热退火对非晶硅太阳电池性能的改善.     

GaAs太阳电池的质子辐照和退火效应

对AlGaAs/GaAs太阳电池进行了质子辐照和热退火实验.质子辐照的能量为325keV,辐照的剂量为5×1010-1×1013cm-2.实验结果表明,质子辐照造成了GaAs太阳电池光伏性能的退化,其中短路电流的退化比其它参数的退化更为明显.退火实验结果表明,200℃的低温退火可以使得辐照后的电池的光伏性能得以部分恢复.此外,实验结果还指出,在GaAs太阳电池表面加盖一层0.5mm的硼硅玻璃盖片可以明显地减少质子辐照对GaAs太阳电池性能的损伤.     

GaAs太阳电池的质子辐照和退火效应(英文)

对 Al Ga As/Ga As太阳电池进行了质子辐照和热退火实验 .质子辐照的能量为 32 5 ke V,辐照的剂量为 5×10 1 0— 1× 10 1 3cm- 2 .实验结果表明 ,质子辐照造成了 Ga As太阳电池光伏性能的退化 ,其中短路电流的退化比其它参数的退化更为明显 .退火实验结果表明 ,2 0 0℃的低温退火可以使得辐照后的电池的光伏性能得以部分恢复 .此外 ,实验结果还指出 ,在 Ga As太阳电池表面加盖一层 0 .5 mm的硼硅玻璃盖片可以明显地减少质子辐照对 Ga As太阳电池性能的损伤     

基于高效体异质结的聚合物太阳电池研究

介绍了体异质结聚合物太阳电池的基本原理,并分析了限制体异质结有机太阳电池转化效率的因素。从提高激子的产生效率及其解离效率、电极对电荷的引出效率、电池的稳定性以及电池的光谱吸收范围四个方面,综述了提高体异质结聚合物太阳电池能量转化效率的方法。     

Time‐Dependent Morphology Evolution by Annealing Processes on Polymer:Fullerene Blend Solar Cells

Changes in the nanoscale morphologies of the blend films of poly (3‐hexylthiophene) (P3HT) and [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester (PCBM), for high‐performance bulk‐heterojunction (BHJ) solar cells, are compared and investigated for two annealing treatments with different morphology evolution time scales, having special consideration for the diffusion and aggregation of PCBM molecules. An annealing condition with relatively fast diffusion and aggregation of the PCBM molecules during P3HT crystallization results in poor BHJ morphology because of prevention of the formation of the more elongated P3HT crystals. However, an annealing condition, accelerating PCBM diffusion after the formation of a well‐ordered morphology, results in a relatively stable morphology with less destruction of crystalline P3HT. Based on these results, an effective strategy for determining an optimized annealing treatment is suggested that considers the effect of relative kinetics on the crystallization of the components for a blend film with a new BHJ materials pair, upon which BHJ solar cells are based.     

Modification of PCBM Crystallization via Incorporation of C60 in Polymer/Fullerene Solar Cells

The morphological effects of the incorporation of C₆₀ into blended thin‐films of poly(3‐hexylthiophene) and [6,6]‐phenyl C₆₁ butyric acid methyl ester (PCBM) are investigated. The results show that addition of C₆₀ readily alters the growth‐rate and morphology of PCBM crystallites under different environmental conditions. The effect of C₆₀ on the growth of large PCBM crystallites is thoroughly characterized using optical microscopy, electron microscopy and UV‐visible absorption spectroscopy. Results show that C₆₀ incorporation modifies fullerene aggregation and crystallization and greatly reduces the average crystallite size at C₆₀ loadings of ≈50 wt% in the fullerene phase. Organic field‐effect transistors (OFETs) are prepared to evaluate the electron mobility of PCBM/C₆₀ films and organic solar cells (OSCs) are fabricated from mixed‐fullerene active layers to evaluate their performance. It is demonstrated that the use of fullerene mixtures in organic electronic applications is a viable approach to produce more stable devices and to control the growth of micrometer‐sized fullerene crystals.     

Improved All‐Polymer Solar Cell Performance by Using Matched Polymer Acceptor

By the introduction of different building blocks and side‐chains, a series of donor–acceptor type polymer acceptors containing naphthalene diimide have been successfully prepared. The theoretical and experimental results show that the molecular design effectively tunes the energy levels, solubility, and coplanarity of the acceptor polymers. The intermolecular packing, which has been considered as a key factor in the bulk heterojunction morphology, has been adjusted by changing the coplanarity. As a result of improved morphology and fine‐tuned energy levels, a power conversion efficiency of 6.0% has been demonstrated for the optimized devices, which is among the highest‐efficiencies for reported all‐polymer solar cells. The improved device performance may be attributed to the resemble crystallinity of the donor/acceptor polymers, which can lead to the optimal phase separation morphology balancing both charge transfer and transport.     

Performance Optimization of Polymer Solar Cells Using Electrostatically Sprayed Photoactive Layers

Polymer solar cells (PSCs) are fabricated using a novel film deposition method, the electrostatic spray (e‐spray) technique. Stable atomization and uniform deposition of the polymer blend by e‐spray are achieved by manipulating the solution concentration, the solvent composition, and the electric field. The performance of PSCs is primarily influenced by the inherent film morphology of the e‐sprayed polymer‐blend active layers, which is significantly different from that of the conventional films that are formed using the spin‐coating (SC) method. The intrinsically formed interfacial boundaries between the e‐sprayed blend pancakes resist charge transport, which unfavorably influences device efficiency. The internal series resistance (R_S) of the PSCs that are formed using the e‐spray method (e‐spray‐PSC) is significantly reduced by a solvent vapor soaking (SVS) treatment in addition to the conventional thermodynamic nanomorphology controls. The detailed relationship between the morphologies (film morphology and internal nanomorphology) and the R_S is revealed using impedance spectroscopy. The performance of the e‐spray‐PSCs is comparable to those of the PSCs that are fabricated using the SC method under identical conditions. Therefore, the e‐spray method can be used to fabricate ultralow‐cost PSCs, because of the performance results combined with the intrinsic advantages that the e‐spray method is simple and has a low materials loss.     

Abrupt Morphology Change upon Thermal Annealing in Poly(3‐Hexylthiophene)/Soluble Fullerene Blend Films for Polymer Solar Cells

The in situ morphology change upon thermal annealing in bulk heterojunction blend films of regioregular poly(3‐hexylthiophene) (P3HT) and 1‐(3‐methoxycarbonyl)‐propyl‐1‐phenyl‐(6,6)C₆₁ (PCBM) is measured by a grazing incidence X‐ray diffraction (GIXD) method using a synchrotron radiation source. The results show that the film morphology—including the size and population of P3HT crystallites—abruptly changes at 140 °C between 5 and 30 min and is then stable up to 120 min. This trend is almost in good agreement with the performance change of polymer solar cells fabricated under the same conditions. The certain morphology change after 5 min annealing at 140 °C is assigned to the on‐going thermal transition of P3HT molecules in the presence of PCBM transition. Field‐emission scanning electron microscopy measurements show that the crack‐like surface of blend films becomes smaller after a very short annealing time, but does not change further with increasing annealing time. These findings indicate that the stability of P3HT:PCBM solar cells cannot be secured by short‐time annealing owing to the unsettled morphology, even though the resulting efficiency is high.     

Overcoming the PCBM/Ag Interface Issues in Inverted Perovskite Solar Cells by Rhodamine-Functionalized Dodecahydro-Closo-Dodecaborate Derivate Interlayer

Efficient modification of the interface between metal cathode and electron transport layer are critical for achieving high performance and stability of the inverted perovskite solar cells (PSCs). Herein, a new alcohol-soluble rhodamine-functionalized dodecahydro-closo-dodecaborate derivate, RBH, is developed and applied as an efficient cathode interlayer to overcome the (6,6)-phenyl-C₆₁ butyrie acid methyl ester (PCBM)/Ag interface issues. By introducing RBH cathode interlayer, the functions of the interface traps passivation, interfacial hydrophobicity enhancement, interface contact improvement as well as built-in potential enhancement are realized at the same time and thus correspondingly improve the device performance and stability. Consequently, a power conversion efficiency (PCE) of 21.08% and high fill factor of 83.37% are achieved, which is one of the highest values based on solution-processed MAPbI₃/PCBM heterojunction PSCs. Moreover, RBH can act as a shielding layer to slow down moisture erosion and self-corrosion. The PCE of the RBH devices still maintain 84% for 456 h (85 °C @ N₂), 87% for 360 h (23 °C @ relative humidity (RH) 35%) of its initial PCE value, while the control device can only maintain ≈23%, 58% of its initial PCE value under the same exposure conditions, respectively.     

Suppressing Kinetic Aggregation of Non-Fullerene Acceptor via Versatile Alloy States Enables High-Efficiency and Stable Ternary Polymer Solar Cells

Despite considerable advances devoted to improving the operational stability of organic solar cells (OSCs), the metastable morphology degradation remains a challenging obstacle for their practical application. Herein, the stabilizing function of the alloy states in the photoactive layer from the perspective of controlling the aggregation characteristics of non-fullerene acceptors (NFAs), is revealed. The alloy-like model is adopted separately into host donor and acceptor materials of the state-of-the-art binary PM6:BTP-4Cl blend with the self-stable polymer acceptor PDI-2T and small molecule donor DRCN5T as the third components, delivering the simultaneously enhanced photovoltaic efficiency and storage stability. In such ternary systems, two separate arguments can rationalize their operating principles: (1) the acceptor alloys strengthen the conformational rigidity of BTP-4Cl molecules to restrain the intramolecular vibrations for rapid relaxation of high-energy excited states to stabilize BTP-4Cl acceptor. (2) The donor alloys optimize the fibril network microstructure of PM6 polymer to restrict the kinetic diffusion and aggregation of BTP-4Cl molecules. According to the superior morphological stability, non-radiative defect trapping coefficients can be drastically reduced without forming the long-lived, trapped charge species in ternary blends. The results highlight the novel protective mechanisms of engineering the alloy-like composites for reinforcing the long-term stability of NFA-based ternary OSCs.