Shun Watanabe

A novel route of molecular doping in organic semiconductors is demonstrated to achieve high carrier concentration.

The Langmuir-Blodgett (LB) and Langmuir-Schaefer techniques facilitate thermodynamic favorability at an air-water interface, at which nanoscale molecular aggregations can be manipulated by micrometer- or millimeter-scale mechanics. The customary use of an aqueous subphase has limitations in the available temperature and spread materials. We present a general strategy to replace the aqueous subphase with an inert, low-vapor-pressure liquid, ethylene glycol. As a representative spread material tha

Charge and thermoelectric transport should be closely correlated with each other; however, little is known regarding the origin of thermopower in semicrystalline $\ensuremath{\pi}$-conjugated polymers, particularly those doped with molecular dopants. It is controversial whether the well-established Mott formula is valid for such conducting polymers, which inevitably have a finite structural disorder. We show that a truly metallic regime that can be realized in a highly crystalline domain gives r

A peak power of 1 TW has been obtained in a XeCl laser with a pulse width of 310 fsec. Amplified spontaneous emission was investigated extensively by changing the gain of wide-aperture discharge amplifiers. As a result, the amplified spontaneous emission content was suppressed to less than 3% in energy through the use of an appropriate spatial filter before the final amplifier and by operating at a low gain level of 4.8%/cm.

A peak power of 4 TW has been obtained in KrF with an output energy of 1.5 J in 390 fsec from an electron-beam-pumped amplifier. The energy of the amplified spontaneous emission was as low as 1.8%. The pulse width was measured by the newly developed third-order autocorrelation technique based on the XeF C–A transition. Amplifiers increased the initial pulse width of 210 fsec to 390 fsec. The process of pulse-width broadening was investigated in detail. It was confirmed that the two-photon proces

Abstract Low-frequency noise generated by a fluctuation of current is a key issue for integrating electronic elements into a high-density circuit. Investigation of the noise in organic field-effect transistors is now sharing the spotlight with development of printed integrated circuits. The recent improvement of field-effect mobility (up to 15 cm 2 V −1 s −1 ) has allowed for organic integrated circuits with a relatively high-speed operation (~50 kHz). Therefore, an in-depth understanding of the