N,N'-diphenylbutyl-3,4,9, 10-perylenebiscarboximide (PTCDI-C4Ph) were characterized by optical and electrochemical methods. A device with an ITO/PTCDI-C4Ph (approximate to 2 mu m)/Al structure was fabricated to measure mobility by time-of-flight techniques. This vacuum deposited organic layer was an amorphous state. Electrons were observed faster than holes. The electron and hole mobilities were 1.8 x 10(-4) cm(2)/V s and 1.1 X 10(-4) cm(2)/Vs under the electric field of 500 (V/cm)(1/2), respectively. This result shows that this organic compound is a good candidate for an n-type conduction. (C) 2004 Elsevier B.V. All rights reserved.