Picene is a phenacene-type aromatic hydrocarbon molecule with five benzene rings. We have fabricated picene single crystal (SC) field-effect transistors (FETs) with solid gate and ionic liquid gate dielectrics. Although the picene SC FET showed a large hole-injection barrier without any modification of interface between source/drain electrodes and picene SC, such a large hole-injection barrier could be effectively reduced by modifying the interface with tetracyanoquinodimethane (TCNQ). Picene SC FET with an HfO2 gate dielectric and TCNQ-coated electrodes shows p-channel characteristics with a smooth hole injection and a field-effect mobility more than 1 cm2 V–1 s–1 in two-terminal measurement. Picene SC FET could be operated even in bottom-contact structure by modifying the interface with octanethiol. Furthermore, picene SC FET operated with ionic liquid gate dielectric, [1-butyl-3-methylimidazolium][hexafluorophosphate], showing the field-effect mobility of 1.8 × 10–1 cm2 V–1 s–1 and low absolute value, 1.9 V, of threshold voltage.

X-ray diffraction illustrates that a two-dimensional smectic liquid crystal is formed in a melting process of an anisotropic, incommensurate monolayer of «-propanol physisorbed on graphite. In this phase a hydrogen-bonded head-to-head association of molecules is arranged in rows with their long axes on average normal to the row. Parallel to the rows, there is only short-range translational order of the molecules.PACS numbers: 61.10. My, 61.30.Eb, 64.70.Dv, 68.35.Rh The prediction of dislocation-mediated melting theory [1-3] that the melting of a two-dimensional (2D) solid could be fundamentally diflFerent from that observed in ordinary three-dimensional (3D) systems has caused a hot controversy among both theorists and experimentalists in the past decade [4][5][6][7][8][9][10][11][12]. Most of these studies, however, are concerned with isotropic monolayers and the melting of an anisotropic monolayer seems to have received little attention to date [7,8,10,13]. The theory [14] predicts that an anisotropic 2D solid composed of molecules which do not show mesophases in their 3D solid may melt via the two intermediate phases of twodimensional smectic and nematic liquid crystals. Recently, the 2D smectic mesophase has been observed at the interface between graphite and the melt of neat Az-alkanes by means of scanning tunneling microscopy [15,16]. As the nature of this system is strongly influenced by the molecules in the melt in contact with the monolayer, and the theory considers only the presence of an incommensurate crystalline substrate however, application of the 2D melting theory is difficult. Thus far the occurrence of the 2D smectic liquid crystal, which may permit a comparison with the 2D melting theory, has not been reported.In this Letter we report the results of an x-ray diffraction study of a monolayer AZ-propanol film on graphite. The results provide direct structural evidence that the 2D smectic mesophase occurs in the melting of an anisotropic, incommensurate monolayer of AZ-propanol physisorbed on graphite.

We are reviewing about the method of analyzing wafer surface organic contamination. Although TD/GC-MS is to be used by the SEMI method used now, it is because it is whether all organic compounds are analyzed appropriately and a question. This time, we clarified the problem in experimenting.