有机薄膜太阳能电池

有机太阳能电池作为一种新兴的有着巨大潜力的光电转换器件,吸引了越来越多的关注。综述了有机薄膜太阳能电池主要的两种器件结构的研究进展,即基于无机异质结发展出来的双异质结型有机太阳能电池和基于扩展双层异质结活性层受限的接触面积而提出的体异质结型太阳能电池;阐述了这两种器件结构的工作原理、影响有机太阳能电池光电转换效率的因素以及两种结构的不足之处,并展望了有机太阳能电池发展的广阔前景。     

Overcoming Moisture-Induced Degradation in Organic Solar Cells

Unencapsulated organic solar cells are prone to severe performance losses in the presence of moisture. Accelerated damp heat (85 °C/85% RH) studies are presented and it is shown that the hygroscopic hole-transporting PEDOT:PSS layer is the origin of device failure in the case of prototypical inverted solar cells. Complementary measurements unveil that under these conditions a decreased PEDOT:PSS work function along with areas of reduced electrical contact between active layer and hole-transport layer are the main factors for device degradation rather than a chemical reaction of water with the active layer. Replacements for PEDOT:PSS are explored and it is found that tungsten oxide (WO₃) or phosphomolybdic acid (PMA)—materials that can be processed from benign solvents at room temperature—yields comparable performance as PEDOT:PSS and enhances the resilience of solar cells under damp heat. The stability trend follows the order PEDOT:PSS << WO₃ < PMA, with PEDOT:PSS-based devices failing after few minutes, while PMA-based devices remain nearly pristine over several hours. PMA is thus proposed as a robust, solution-processable hole extraction layer that can act as a one to one replacement of PEDOT:PSS to achieve organic solar cells with significantly improved longevity.     

Recent Progress in All-Small-Molecule Organic Solar Cells

Active layer material plays a critical role in promoting the performance of an organic solar cell (OSC). Small-molecule (SM) materials have the merits of well-defined chemical structures, few batch-to-batch variations, facile synthesis and purification procedures, and easily tuned properties. SM-donor and non-fullerene acceptor (NFA) innovations have recently produced all-small-molecule (ASM) devices with power conversion efficiencies that exceed 17% and approach those of their polymer-based counterparts, thereby demonstrating their great future commercialization potential. In this review, recent progress in both SM donors and NFAs to illustrate structure–property relationships and various morphology-regulation strategies are summarized. Finally, ASM-OSC challenges and outlook are discussed.     

Integrated Perovskite/Bulk-Heterojunction Organic Solar Cells

The recently emerged integrated perovskite/bulk-heterojunction (BHJ) organic solar cells (IPOSCs) without any recombination layers have generated wide attention. This type of device structure can take the advantages of tandem cells using both perovskite solar and near-infrared (NIR) BHJ organic solar materials for wide-range sunlight absorption and the simple fabrication of single junction cells, as the low bandgap BHJ layer can provide additional light harvesting in the NIR region and the high open-circuit voltage can be maintained at the same time. This progress report highlights the recent developments in such IPOSCs and the possible challenges ahead. In addition, the recent development of perovskite solar cells and NIR organic solar cells is also covered to fully underline the importance and potential of IPOSCs.     

Morphology Control Enables Efficient Ternary Organic Solar Cells

Ternary organic solar cells are promising alternatives to the binary counterpart due to their potential in achieving high performance. Although a growing number of ternary organic solar cells are recently reported, less effort is devoted to morphology control. Here, ternary organic solar cells are fabricated using a wide‐bandgap polymer PBT1‐C as the donor, a crystalline fused‐ring electron acceptor ITIC‐2Cl, and an amorphous fullerene derivative indene‐C₆₀ bisadduct (ICBA) as the acceptor. It is found that ICBA can disturb π–π interactions of the crystalline ITIC‐2Cl molecules in ternary blends and then help to form more uniform morphology. As a result, incorporation of 20% ICBA in the PBT1‐C:ITIC‐2Cl blend enables efficient charge dissociation, negligible bimolecular recombination, and balanced charge carrier mobilities. An impressive power conversion efficiency (PCE) of 13.4%, with a high fill factor (FF) of 76.8%, is eventually achieved, which represents one of the highest PCEs reported so far for organic solar cells. The results manifest that the adoption of amorphous fullerene acceptor is an effective approach to optimizing the ternary blend morphology and thereby increases the solar cell performance.     

有机染料共敏化太阳能电池研究进展

近年来,染料敏化太阳能电池由于低成本、高效率而备受人们关注。共同敏化太阳能电池是利用多种染料共同敏化光阳极的新一类染料敏化太阳能电池。共敏化太阳能电池显示出了较单一染料敏化太阳能电池更好的效率和稳定性,具有很好的应用前景。综述了近年来有机染料共同敏化太阳能电池在染料分子结构的设计、半导体的改良等方面所取得的研究进展。     

Interfacial Modification in Organic and Perovskite Solar Cells

Organic bulk heterojunction solar cells (OSCs) and hybrid halide perovskite solar cells (PSCs) are two promising photovoltaic techniques for next‐generation energy conversion devices. The rapid increase in the power conversion efficiency (PCE) in OSCs and PSCs has profited from synergetic progresses in rational material synthesis for photoactive layers, device processing, and interface engineering. Interface properties in these two types of devices play a critical role in dictating the processes of charge extraction, surface trap passivation, and interfacial recombination. Therefore, there have been great efforts directed to improving the solar cell performance and device stability in terms of interface modification. Here, recent progress in interfacial doping with biopolymers and ionic salts to modulate the cathode interface properties in OSCs is reviewed. For the anode interface modification, recent strategies of improving the surface properties in widely used PEDOT:PSS for narrowband OSCs or replacing it by novel organic conjugated materials will be touched upon. Several recent approaches are also in focus to deal with interfacial traps and surface passivation in emerging PSCs. Finally, the current challenges and possible directions for the efforts toward further boosts of PCEs and stability via interface engineering are discussed.     

Printable MoOx Anode Interlayers for Organic Solar Cells

Currently, solution‐processed MoO_x anode interfacial layers (AILs) can only be fabricated by the spin‐coating method in organic solar cells (OSCs), which severely limits their use in practical productions where large‐area printing techniques are used. Herein, a facile method is demonstrated to prepare highly conductive MoO_x (denoted EG:Mo) that can be processed by printing methods such as wire‐bar and blade coatings. The EG:Mo films are prepared by depositing an aqueous solution containing ammonium heptamolybdate (VI) tetrahydrate (NMo) and ethylene glycol (EG) and annealing at 200 °C. UV–vis absorption and X‐ray photoelectron spectroscopy measurements confirm that Mo (VI) can be reduced to Mo (V) by EG, resulting in the n‐doped EG:Mo. Using the EG:Mo as AILs, an OSC based on a PB3T:IT‐M active layer exhibits a power conversion efficiency (PCE) of 12.1%, which is comparable to that of the PEDOT:PSS modified devices. More importantly, EG:Mo AILs can be processed by wire‐bar and blade‐coating methods, and the corresponding devices show PCEs of 11.9% and 11.5%, respectively. Furthermore, the EG:Mo AIL is processed by wire‐bar coating to fabricate a large area device (1.0 cm²), and a PCE of 10.1% is achieved.     

Black Phosphorous Quantum Dots Sandwiched Organic Solar Cells

Black phosphorous quantum dots (BPQDs) possess ambipolar charge transport, high mobility, and a tunable direct bandgap. Here, liquid‐exfoliated BPQDs are used as interlayers to modify both the electron transport layer and hole transport layer in organic solar cells (OSCs). The incorporation of BPQDs is beneficial to the formation of a cascade band structure and electron/hole transfer and extraction. The power conversion efficiency of the BPQDs‐incorporated OSC based on PTB7‐Th:FOIC blend is enhanced from 11.8% to 13.1%. In addition, power conversion efficiency enhancement is also achieved for other nonfullerene and fullerene‐based devices, demonstrating the universality of this interlayer methodology.     

可印刷柔性有机太阳能电池技术创新态势研究

介绍了可印刷柔性有机太阳能电池的相关技术及发展现状,并基于专利对该技术展开了深入的创新研究。从技术的总体趋势、技术重点、技术构成与需求、重要竞争机构及技术生命周期5个方面探讨了该技术的发展现状与趋势,为该领域内相关企业制定战略决策提供参考依据。研究发现可印刷柔性有机太阳能电池正处于快速发展阶段,日本、美国处于领跑地位,各国积极布局以期抢占竞争高位。