Simultaneous measurement of X-ray scattering and photoluminescence during molecular deposition

We present a simultaneous in situ measurement of X-ray scattering and photoluminescence (PL) spectroscopy during organic thin-film growth in a vacuum. We have designed a modified deposition chamber that broadens its utilization and enables complementary information on the structure and optoelectronic properties. In a pilot experiment, we investigated the growth of diindenoperylene (DIP) thin films in real time. We found a direct correlation between PL and grazing-incidence wide-angle X-ray scattering (GIWAXS), showing the formation of a new DIP polymorph starting at a layer thickness of ∼14 nm. Furthermore, we show that the PL signal is more sensitive to the arrangement of the molecules than GIWAXS in the limit of small layer thicknesses. The presented experimental setup paves the way for performing simultaneous PL and X-ray scattering measurements during the growth of various materials suitable for optoelectronic applications.