Polymer Solar Cells: Recent Approaches and Achievements

Abstract

Polymersolar cells have gained wide interest in the past few years for their potential in the field of large-area and low-cost photovoltaic devices. Thanks to rather simple treatments developed in the new millennium, the morphology of polymer solar cells has been optimized at the nanoscale level, leading to high efficient charge-carrier photogeneration and collection. Power conversion efficiency up to 6% and 6.5% have been reported in the literature for solution-processed polymer solar cells in single-junction and tandem configuration, respectively, and a record efficiency of 6.77% has been recently announced. After an introduction into the operational principles and device structure of polymer solar cells, this paper provides an overview of the last-years research activity. In particular, the different treatments successfully performed on polymer active layers, and their beneficial effects on the overall device efficiency are discussed. Subsequently, some significant examples of photoactive materials will be examined, outlining the foremost structure−properties relationships. Some directions for further enhancement of the performance of polymer solar cells will be also introduced, mainly through the fine-tuning of the electronic properties of the active materials

Ternary thiophene–X–thiophene semiconductor building blocks (X=fluorene, carbazole, phenothiazine): Modulating electronic properties and electropolymerization ability by tuning the X core

“…Finally, a comparison between a -(Th-X-Th) n -periodic polymer and the corresponding -(Th-X) none has also been achieved by applying the Suzuki coupling approach to Th-Fluo-Th monomer F 1 and to the corresponding Th-Fluo one f 1 . 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 6 2.…”

“…Conjugated polymeric systems based on thiophene, carbazole or fluorene are among the most promising materials for the development of new generation, highly efficient organic photovoltaic devices [1][2][3]. These monomer units, especially in combination with electron-poor aromatic units, lead to novel polymeric electron donor structures [4][5][6][7][8] that possess a number of properties useful for increasing the photovoltaic response [2], such as an energy level alignment with electron acceptors [9]; a low energy gap which favours the light harvesting and increase the short-circuit current of the device [4]; a fair hole mobility [10] and good solubility in organic solvents and film forming characteristics [11].…”

Optical probes of chain packing structure and exciton dynamics in polythiophene films, composites, and nanostructures

“…[1][2][3][4][5][6] Amenable to solution-processing techniques (e.g. roll-to-roll or ink-jet printing processing), 7,8 as well as an enormous available structural parameter space, semiconducting polymers and polymer blends hold the potential for realizing this goal.…”

An overview of molecular acceptors for organic solar cells

“…In the last two decades, this tendency to move progressively from inorganic to organic-based materials for photovoltaic applications has emerged as the third generation of photovoltaic materials. These devices that contain organic materials in the active layer include dye-sensitized solar cells [1][2][3][4] and donor-acceptor heterojunction based solar cells [5][6][7][8][9]. This last topic has recently been the subject of intensive academic interest and has particularly captured a huge amount of industrial attention due to the rapid increase in power conversion efficiencies (PCE) of these solar cells and their potential for developing flexible, light-weight devices using low-cost production methods.…”