Direct Measurement of Molecular Flux in Organic Molecular Beam Deposition

Mass distribution and molecular flux during sublimation of several functional organic compounds such as tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ), Copper-phthalocyanine and fullerene in ultrahigh vacuum are directly measured using a high-performance quadrupole mass spectrometer. It was confirmed that molecules in a complexed form sublime as individual molecules from a Knudsen cell (K-cell). The dependence of evaporation rate on the temperature of the K-cell was numerically calibrated for the first time.