The electrical characteristics of thermally evaporated triclinic lead phthalocyanine thin films are studied. A number of parameters is evaluated on the basis of the theory of space-charge-limited conduction and the following values are obtained: permittivity E = 3.16 x lo-'' F m-'; hole mobility p x 6.05 x lo-'' m2 V-' s-';room temperature hole concentration p o z 1.60 x 10" m -3 ; concentration of traps per unit energy range at the valence band edge Po z 2.79 x J -' m^3; temperature parameter of trapping distribution IT; x 770 K; total trap concentration N, x 2.97 x The room temperature electrical conductivity o = 1.55 x lO-'OS m-'. C -U measurements confirm that the Au-PbPc interface does not form a Schottky barrier. At low temperatures the capacitance of Au-PbPc-Au devices is temperature insensitive, increasing rapidly above 300 K and saturating at about 400 K. Measurements of thermoelectric power confirm that semiconduction is p-type. Die elektrischen Eigenschaften von thermisch aufgedampften dunnen triklinen Blei-Phtalozyaninschichten werden untersucht. Eine Anzahl von Parametern wird auf der Grundlage der Theorie des raumladungsgegrenzten Stromes berechnet und folgende Werte erhalten: Dielektrizitatskonstante E = 3,16 x lo-" F m -I ; Locherbeweglichkeit p z 6,05 x lo-'' m 2 V-'s-'; Raumtemperaturlocherkonzentration p o z 1,60 x 10" m-3; Konzentration der Haftstellen pro Energieeinheit an der Valenzbandkante Po z 2,79 x J-' m -3 ; Temperaturparameter der Haftstellenverteilung ?; = 770 K; Gesarnthaftstellenkonzentration N, z 2,97 x loz3 ~t -~. Die elektrische Leitfahigkeit bei Zimmertemperatur betragt u = 1,55 x 10l o S m -I . C-U-Messungen bestatigen, dal3 die Au-PbPc-Grenzflache keine Schottky-Barnere bildet. Bei tiefen Temperaturen ist die Kapazitat von Au-PbPc-Au-Bauelementen temperaturunabhangig, steigt oberhalb 300 K schnell an und sattigt bei etwa 400 K. Messungen der Thermospannung bestatigen den p-Halbleitungstyp.

Infrared absorption spectra are presented for freshly evaporated lead phthalocyanine, oxygen doped lead phthalocyanine and material which has been vacuum annealed. The spectra allow characterization of films for utilization in gas sensors and FET structures.

The electrical properties of oxygen‐doped thin films of triclinic lead phthalocyanine with mixed (Al, Au) electrodes are studied. AuPbPcAl and AlPbPcAu structures show different behaviour due to the varying oxygen distributions in the PbPc and the existence of an interfacial aluminium oxide layer in the latter case. At low voltages both types of device show Schottky diode behaviour. For AuPbPcAl structures the model of Cheung and Cheung is used to derive diode parameters. Barrier heights and widths are determined as a function of applied voltage and trap densities, hole concentrations, and the temperature parameter of the trapping are found to be consistent with reported values. The present results emphasise the role of oxygen doping and interfacial oxide layers in determination of the electrical behaviour of PbPc based devices.

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The poly(ethylene oxide) polymer (PEO) is doped with fine powder of MnCl 2 salt and thin films of thickness (50-150 mm) with salt content (0, 5, 10, 15, and 20 wt%) are obtained. The AC electrical conductivity and dielectric constants are studied as a function of temperature through an impedance technique. It is found that AC conductivity increases and the calculated activation energy decreases with increasing temperature due to enhancement of the ionic conduction in the film bulk. The dielectric constants of the doped membranes increase with temperature. It is found that the peak value of the tanloss is shifted to a higher frequency at higher temperatures. The dielectric behavior is explained on the basis of interfacial (space charge) polarization, dipolar polarization, and hindrance of the polymer matrix.