Conduction of Electric Current to Organic Molecules observed by Carrier Transport Mobility Measurements

Organic semiconductors have been studied for many years, but electric current conduction through organic materials has proven difficult in practice. To evaluate the carrier mobility of newly synthesized modified polyacenes, we prepared suitable techniques for determining the physical properties of the polyacenes from electrical measurements. In a transparent electrode cell based on a low-melting-point material, we observed the dark-current dependence on the cooling rate and evaluated the sample impurity. We then developed a vertical field-effect transistor (FET) device for high- melting-point materials that easily measures the transconductance of a single drop of a sample solution. The vertical FET device provides indirect evidence of Marcus’ theory of electric conduction phenomena in aggregated organic materials.