UTILIZATION OF CONDUCTING POLYMERS IN RECTIFYING JUNCTION CONSTRUCTION - DARK CHARACTERISTICS AND PHOTOVOLTAIC PROPERTIES

The electrical characteristics of the junction obtained by depositing poly(4,4'-dipentoxy-2,2'-bithiophene) on n-type silicon have been inve stigated in the dark and under white as well as monochromatic illumina tion. The dark forward current is space charge limited at forward bias > 0.2 V, whereas it has an exponential trend for very low forward vol tages. A Schottky barrier formation at the poly(ET2)/n-Si interface is demonstrated. The barrier height values, obtained both from the Mott- Schottky plot and from the dependence of the open-circuit voltage on t he short-circuit current, are very similar. The short-circuit current is a linear function of the incident light intensity, as expected for silicon solar cells. The analysis of the spectral response of the junc tion suggests that the photocurrent is mainly due to silicon.