Amplified Emission and Field-Effect Transistor Characteristics of One-Dimensionally Structured 2,5-Bis(4-biphenylyl)thiophene Crystals

One-dimensional (1D) structures of 2,5-bis(4-biphenylyl)thiophene (BP1T) crystals are fabricated for light amplification and field-effect transistor (FET) measurements. A strip-shaped 1D structure (10 m width) made by photolitography of a vapor-deposited polycrystalline film shows amplified spontaneous emission and lasing oscillations under optical pumping. An FET fabricated with this 1D structure exhibits hole-conduction with a mobility of h = 8.0×10−3 cm2/Vs. Another 1D-structured FET is fabricated with epitaxially grown needle-like crystals of BP1T. This needle-crystal FET exhibits higher mobility of h 034 cm2/Vs. This improved hole mobility is attributed to the single-crystal channel of epitaxial needles while the grain boudaries in the polycrystalline 1D-structure decrease the carrier transport.