Characterisation of organic photovoltaics by synchrotron soft X-ray techniques

The use of advanced synchrotron X-ray spectroscopy and microspectroscopy techniques can probe the nanoscale structure of organic solar cells. Near Edge X-ray Absorption Fine Structure Spectroscopy (NEXAFS) is able to determine chemical composition and molecular tilt angles at interfaces with a depth sensitivity varying from ~4-10nm. Scanning Transmission X-ray Microscopy is able to determine composition of organic components in a ternary blend to within 10%, while achieving a spatial resolution of ~30nm. These techniques have been used to deliver novel results on the structure of interfaces and nanoscale morphology in organic photovoltaic devices. The results allow a greater understanding of the morphology of organic photovoltaics and enhance the uses of synchrotron X-ray spectroscopy.