Browsing by Author "Goro, Girma"
Now showing 1 - 1 of 1
Results Per Page
Sort Options
Item Electrical Properties of Junctions between Aluminium and POLY (3-(2,5-Dioctylphenyl)-Thiophene) (PDOPT)(Addis Ababa University, 1998-06) Goro, Girma; Workalemahu, Bantikassegn (PhD)This thesis is based on the study of interface properties between a reactive metal and a neutral conjugated polymer. The polymer used is poly(3-(2,5-dioctylphenyl)-thiophene) (PDOPT). The techniques employed are absorption spectroscopy, current-voltage and complex impedance spectroscopy measurements. The absorption measurement reveals that the polymer, PDOPT, has an energy gap of about 2.02 eV and hence it belongs to the class of semiconducting materials. The I-V characteristic of AVPDOPTIITO structure shows symmetrical but non-ohmic curves. The complex impedance analysis exhibits a single semicircle whose diameter depends on the magnitude of the applied voltage. For smaller values of the applied voltage, both for the reverse and forward biases, the extrapolated diameter of the semicircle is larger. This value is consistent with the result of the I-V measurements. So this device, AVPDOPTIITO, may be considered as a metal-semiconductor device with no rectifying Schottky barrier formation at the AVPDOPT interface. The small value of current may be due to high bulk resistance of the polymer, as well as the probable formation of thick oxides of aluminium