(cest2017_00695) Dehydration of Tungsten Oxide Hole Extraction Layers via Microwave Annealing for Efficiency and Lifetime Enhancement in Organic Solar Cells

摘要

A significant contribution to the efficiency and lifetimeenhancement of organic solar cells is due to the successfulengineering of the metal contact/organic interface byintroducing appropriate interlayers. In the current work weshow that a short microwave post-annealing treatment inair of an under-stoichiometric tungsten oxide (WOx) holeextraction layer significantly enhanced the performanceand lifetime of an organic solar cell based on the poly(3-hexylthiophene):[6,6]-phenylC70butyric acid methyl ester(P3HT:PC70BM) blend. The enhanced performance ismainly driven by the increased work function of the anode,the reduced series and increased shunt resistances and alsothe higher charge generation efficiency, the reducedrecombination losses and the improved hole transporttowards the anode contact. In addition, the lifetime of thedevices with the microwave annealed WOx interlayers wasalso significantly improved compared to those with the asdepositedWOx and, especially, to those with the PEDOTPSSinterlayer. The above were attributed to the effectivedehydration which was also followed by the weakstructural transformation and crystallization of the WOxlayer during microwave annealing, as revealed by the x-rayand infrared measurements.