Organic light-emitting diodes based on layered films of thiophene/phenylene co-oligomers

Abstract We have fabricated p–n junctions using a combination of p- and n-type thiophene/phenylene co-oligomer (TPCO) thin films and applied them to organic light-emitting diodes (OLEDs). We made two types of devices using the different p-type TPCOs. Both the devices showed current-injected light emissions and high rectification ratios (~ 10 2 –10 4 ). The one type of the devices produced brighter surface emissions and higher external quantum efficiencies (0.17%) than the other. The results indicated that the p–n junction comprising layered TPCOs showed good functionality.