Low Temperature Evaporation

Recently, there has been a surge of interest in the use of Physical Vapour Deposition (PVD) methods for forming thin films of materials that have relatively low vapourisation temperatures (i.e., high volatility). Examples include small-molecule compounds with properties useful for organic electronics applications such as OFETs, OLEDs and OPVs.

Vaporisation of these materials usually takes place at <600 °C. This is much lower than, for example, metals used for contact electrodes. Furthermore, for organic materials, the onset of vaporisation under vacuum conditions is extremely sensitive to temperature, i.e., a small temperature increase can make the difference between a zero deposition rate and ejection from the source of the entire load!