Energetics of molecular interfaces

The energetics of molecular interfaces, used in determining the properties and performance of materials were described. A combination of ultraviolet photoemission spectroscopy measurement of highest occupied molecular orbital and inverse photoemission spectroscopy measurements of the lowest unoccupied molecular orbital of an organic monolayer was used to determine the single particle gap of the molecular materials. It was found that determining Fermi level position of the metal contact on the same energy scale, can derive energy barrier for electrons and hole injection across the interface. It was also found that structural defects, which give rise to new electronic states, can extend into the band gap of the pristine materials.