The microscopic mechanisms behind the very high mobility in rubrene single-crystal transistors achieved by interface treatments with self-assembled monolayers (SAMs) have been clarified by using field-induced electron spin resonance (FI-ESR). Clearly observed FI-ESR signals exhibit extremely narrow linewidths owing to the very high carrier mobility. The precise angular dependence of FI-ESR g values shows that crystallinity in the semiconductor channel is unchanged by the SAM treatments. The trapping time of charge carriers at the interface directly evaluated from the ESR linewidth greatly decreases from ∼700 to ∼60 ps concomitant with the remarkable improvement in mobility because of the SAM treatments.

Field-induced charge carriers at the semiconductor/dielectric interface of rubrene single-crystal field-effect transistors (RSC-FETs) were studied by ESR. We fabricated bottom-contact RSC-FETs to be used for ESR measurements by laminating RSCs onto SiO2 and polymer/SiO2 gate dielectric surfaces. The observed ESR spectra depict a minimal dependence on gate voltage, whose result is in sharp contrast to those obtained using RSC-FETs fabricated by the deposition of a parylene C gate dielectric. This behavior indicates that few deep trap levels are generated by the lamination technique. The dependence of ESR intensity on drain voltage was also investigated using gradual channel approximation.

Purpose] We studied the characteristics of baseball club members with regard to the position of the scapula and the relationship between the position of the scapula and the strength of external and internal rotators in order to make injury prevention measures from injury for baseball players.[Subjects] The subjects were baseball club members (29 men) and soccer club members (14 men) and ordinary students (12 men) who did not play sports regularly at the Health Science University. [Methods] We evaluated elevation depression and rotation of scapulae of baseball club members and compared their values to those of the soccer club members and the ordinary students who did not play sports regularly at the Health Science University. We then compared strength of external and internal rotators among the three groups based on the position of scapulae: elevated, depressed and intermediate. [Results] The position of scapulae of the baseball club members tended to be depressed compared to the ordinary students. The elevated scapula group tended to have stronger external rotators than the other two groups, but there was no relationship with the rotation of the scapula. [Conclusion] The results suggest that the scapula position in the resting standing position influences the strength of the external rotator. Key words: position of the scapula, strength of external and internal rotators, baseball