A time-of-flight study of a new hyperbranched oligomer film composed of thiophene and N , N , N′ , N′ -tetraphenyl-1,3-phenylenediamine

The highly soluble hyperbranched oligothiophene (SH-oligothiophene), which is composed of bithiophene and N,N,N′,N′-tetraphenyl-1,3-phenylenediamine groups, is newly prepared and the photocarrier transport property of the SH-oligothiophene film prepared by spin coating from a chloroform solution is investigated by a time-of-flight method. Transient photocurrent profiles indicate that hole carriers drift preferentially compared with electrons and that dispersive transport characteristics are obtained.