  Even though the term `organic electronics' evokes rather organic devices, a
significant part of its scope deals with physical properties of `active
elements' such as organic films and interfaces. Examination of the film growth
and the evolution of the interface formation are particularly needful for the
understanding a mechanism controlling their final properties. Performing such
experiments in an ultra-high vacuum allows both to `stretch' the time scale for
pseudo real-time observations and to control properties of the probed systems
on the atomic level. Photoemission technique probes directly electronic and
chemical structure and it has thereby established among major tools employed in
the field. This review primarily focuses to electronic properties of oligomeric
molecular films and their interfaces examined by photoemission. Yet, it does
not aspire after a complete overview on the topic; it rather aims to otherwise
standard issues encountered at the photoemission characterization and analysis
of the organic materials, though requiring to consider particularities of
molecular films in terms of the growth, electronic properties, and their
characterization and analysis. In particular, the fundamental electronic
parameters of molecular films such as the work function, the ionization energy,
and the interfacial energy level alignment, and their interplay, will be
pursued with considering often neglected influence of the molecular
orientation. Further, the implication on the band bending in molecular films
based on photoemission characterization, and a model on the driving mechanism
for the interfacial energy level alignment will be addressed.
