https://novaprd-lb.newcastle.edu.au/vital/access/manager/Index ${session.getAttribute("locale")} 5 NEXAFS microscopy of polymeric materials: successes and challenges encountered when characterizing organic devices https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:8932 Sat 24 Mar 2018 11:13:13 AEDT ]]> Evolution of the nanomorphology of photovoltaic polyfluorene blends: sub-100 nm resolution with x-ray spectromicroscopy https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:4833 95%) implies that there is significant intermixing within the 85 nm structures, indicating that a hierarchy of phase separation exists even on the length scale of less than 100 nm. With annealing up to 160°, close to the Tg of the components, there is little change in the feature sizes observed by STXM,although an increase in variation of the composition is observed.With annealing above 160°C the imaged features begin to evolve in size,increasing to 225 nm in extent, alongside large changes in composition with annealing to 200°C. Comparing the evolution of morphology imaged by STXM with the change in photoluminescence quenching with annealing, we propose that phase separation first evolves via the evolution of relatively pure phases on the length scale of a few to tens of nanometres within the larger 85 nm structures. Once the length scale of compositional fluctuations exceeds 85 nm (for anneal temperatures above 160°C) the hierarchy of phase separation is lost and the subsequent morphological evolution is readily imaged by STXM.Applying the results of an exciton diffusion and quenching model, we find good agreement between the size of the domains measured by STXM (above 180°C) and the results of the model for an exciton diffusion length of 15 nm. The growth in domain size and towards purer structures has also been observed with resonant soft x-ray scattering.]]> Sat 24 Mar 2018 07:18:51 AEDT ]]>