A Schottky type diode has been constructed with the electrochemically prepared copolymer having pyrrole and N-methylpyrrole units and a low work function metal (In). The heat treatment of the copolymer in air was performed in order to stabilize the electrical characteristics of the device before the deposition of a blocking electrode. The electrical properties have been investigated by means of I–V and C–V measurements. The diode quality factor and the barrier height have been obtained to be n=1.2 and ψb=0.81 V by applying a thermionic emission theory, respectively. At high current densities in the forward direction, a space-charge-limited current has been observed. This observation would be due to the charge-injection across the thin oxidized layer which would be formed during the heat treatment of the copolymer in air. Other junction parameters have been also determined by means of C–V measurements.

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A high resolution laser induced fluorescence (LIF) system has been developed to measure the flow velocity field of neutral particles in an electron-cyclotron-resonance argon plasma. The flow velocity has been determined by the Doppler shift of the LIF spectrum, which is proportional to the velocity distribution function. Very high accuracy in velocity determination has been achieved by installing a saturated absorption spectroscopy unit into the LIF system, where the absolute value and scale of laser wavelength are determined by using the Lamb dip and the fringes of a Fabry-Perot interferometer. The minimum detectable flow velocity of a newly developed LIF system is +/-2 m/s, and this performance remains unchanged in a long-time experiment. From the radial measurements of LIF spectra of argon metastable atoms, it is found that there exists an inward flow of neutral particles associated with neutral depletion.

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