Optical device

A method of forming an optical device comprising the steps of:

• providing a substrate comprising a first electrode capable of injecting or accepting charge carriers of a first type;
• forming over the first electrode a first layer that is at least partially insoluble in a solvent by depositing a first semiconducting material that is free of cross-linkable vinyl or ethynyl groups;
• subjecting the first layer to heat treatment;
• forming a second layer in contact with the first layer and comprising a second semiconducting polymer by depositing a second semiconducting material from a solution in the solvent;
• and
• forming over the second layer a second electrode capable of injecting or accepting charge carriers of a second type.

A method of forming an optical device comprising the steps of:

• providing a substrate comprising a first electrode capable of injecting or accepting charge carriers of a first type;
• forming a first layer over the first electrode by depositing a first semiconducting polymer comprising fluorene repeat units, the first semiconducting polymer being free of cross-linkable vinyl or ethynyl groups and being, at the time of deposition, soluble in a solvent;
• subjecting the first layer to one or more of heat treatment, vacuum treatment or ambient drying treatment;
• forming a second layer in contact with the first layer and comprising a second semiconducting polymer by depositing a second semiconducting polymer from a solution in the solvent;
• and
• forming over the second layer a second electrode capable of injecting or accepting charge carriers of a second type.