Annealing-free highly crystalline solution-processed molecular metal oxides for efficient single-junction and tandem polymer solar cells

Abstract

Polyoxometalate (POM) layers have been used to realize efficient and long-term stable single-junction polymer photovoltaic devices with diverse configuration and donor:acceptor combination in the photoactive blend and polymer tandem cells through functioning as effective hole extraction layers and, also, as recombination layers in the interconnecting unit of the tandem cell. Their unique properties, such as their extremely high work function (W F ) of 6.0-6.2 eV, their high degree of crystallinity without any post annealing requirements and, especially, the position of their lowest unoccupied molecular orbital (LUMO), were used to control the characteristics of optoelectronic devices. It was found that POMs having a deep LUMO level lying below the highest occupied molecular orbital (HOMO) of the donor polymer are highly beneficial for device operation due to the interfacial p-doping of the latter. We demonstrated conventional and reverse structure single-junction cells reaching an efficiency of 7.9% in the latter case and a tandem cell with an efficiency of 9.9% using an all 2 solution processed inverted structure, where a POM layer simultaneously offers enhanced hole extraction in the sub-cells and minimal losses in the recombination unit. The specific properties of four POM materials and their role as functional layers in those different types of polymer photovoltaic devices are discussed.15% are feasible for polymer tandem solar cells with an optimized pair of absorber materials with different

Significant Effect of Fluorination on Simultaneously Improving Work Function and Transparency of Anode Interlayer for Organic Solar Cells

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cathode interlayer materials that are successfully used in the efficient OSCs, anode interlayer (AIL) materials with satisfactory performances are rather rare. [18][19][20][21] At present, the lack of ideal AILs has seriously impeded the pace toward practical application of OSCs.Currently, the enhancement of work function (WF) is the most critical issue for the development of AILs. [18][19][20][21] At present, the lack of ideal AILs has seriously impeded the pace toward practical application of OSCs.

Currently, the enhancement of work function (WF) is the most critical issue for the development of AILs.

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Surface passivation effect by fluorine plasma treatment on ZnO for efficiency and lifetime improvement of inverted polymer solar cells

“…[14][15][16][17][18][19][20][21][22][23][24][25] The energy levels of ZnO (conduction band bottom and valence band top) are at around -4.4…”

Recent Progress in the Application of Polyoxometalates for Dye‐sensitized/Organic Solar Cells

“…It was attributed to the effect of PTA in impeding the back electron transfer, and increasing the ionic conductivity of the polymer electrolytes. [72] The redox potential value of the Co III /Co II couple matched with the potential of dye and the TiO 2 conducting band.…”