Crystallisation behaviour of PCDTBT in thin films

Chapter 1 introduces the reasons behind this study, the importance and applications of PCDTBT in organic electronic devices, thus the importance of understanding how confinement in thin films influences the crystallisation of this polymer which will have an impact on the
electronic properties of the material. Chapter 2 describes the analytical techniques used (ellipsometry,
atomic force microscopy and grazing incidence X-ray scattering) and their importance
for this study. In chapter 3 is reported the thermal protocol that allowed the understanding of
the crystallisation of PCDTBT; ellipsometry, GIWAXS and AFM results are reported in order
to understand the importance of the protocol and also aid the comprehension of the rest of the
thesis. Chapter 4 describes how different annealing temperatures influence the crystallisation
kinetics and the amount of crystallinity in a sample. Chapter 5 looks in detail at a phenomenon
occurring in the film that was quite unpredicted: the ellipsometry data are used to follow the
change of the thickness of the film under the thermal treatment explained in chapter 3; an
initial shrinking at the ellipsometry shows the crystallisation phenomenon, but what is causing
a second expansion which is following the crystallisation. In chapter 6 is finally reported the
influence of the film thickness on the crystallisation properties of the material; the influence
of the two interfaces on its ordering is key in understanding how to improve the efficiency of
organic electronic devices.