Origin of carrier types in intrinsic organic semiconductors

A study revealed the actual relationship between the electronic states and the carrier types in electrical conduction of organic semiconductors. The study demonstrated the construction of a UHV system for measuring electrical conduction and the photoelectron spectrum, using the same specimens in situ. Aluminum-chlorophthalocyanine (AlPcCl) was selected as a model material to fabricate field-effect transistors (FETs). AlPcCl was regarded as having p-type semiconductor and n-type nature. The AlPcCl was considered the most appropriate material for discussing the decisive factor of the carrier type in relation to various physical properties. All the investigations were performed on the basis of the UHV system, while the electronic states of AlPcCl-Au interfaces were investigated by controlling the surface condition of the Au electrode.