Comparison of physical and chemical techniques to create nanostructured composite Hole Transport Layers for Perovskite Solar Cells

摘要

The addition of metal nanoparticles (NP) inside polymeric Hole Transport Layers (HTL) or at their interfaces is a valuable strategy to enhance the efficiency up to 70% in organic solar cells [1]. This is attributed to several mechanisms, including improvements in morphology, conductivity as well as plasmonic phenomena. In this work, this strategy is analyzed with a view to its application to Perovskite Solar Cells. Silver NPs have been synthesized via both chemical (AgNO_3 reduction) and physical routes (magnetron sputtering and thermal evaporation). The capability of thermal post treatment to promote the NP formation has been evaluated. Their integration into the poly (3,4-ethylenedioxythiophene) polystyrenesulfonate PEDOT:PSS is performed by spin coating the polymer on the top of NP layer, or by co-deposition of metal NPs and HTL solutions. These nanostructured composite HTLs show increases in thin film conductivity up to 6 times. Plasmonic absorbance which could possibly be exploited to enhance solar cell performance has also been observed.