Experimental and numerical study of pentacene molecular beam seeded in the free jet of Helium

A problem of increasing interest in the last years, both for mass-spectrometry and for deposition of organic semiconductor films, is to increase and control the flux of large organic molecules seeded in a carrier gas expanding towards a skimmer. This paper deals with experimental and numerical investigations on the dependence of kinetic energy of Pentacene molecules from the gas flow rate. Pentacene is a very important molecule in the field of organic semiconductors where it plays the role of a prototypical system for molecular electronics. The numerical results concerning the flow rate of helium through an optimized capillary as well as the kinetic energy of Pentacene molecules in the beam are in qualitative agreement with the results of measurements paving the way to the optimization of the device.