Thin film transistors comprising carbon nanotube networks encapsulated by a polymeric layer and methods for the manufacture thereof

A method of selecting a polymeric layer to provide a desired threshold voltage for a thin film transistor, the thin film transistor comprising:

• a source electrode, a drain electrode and a gate electrode;
• a semiconducting channel comprising a network of carbon nanotubes, the carbon nanotubes electrically coupled to the source electrode and drain electrode and electrically insulated from, but capacitively coupled to, the gate electrode;
• and
• the polymeric layer coupled to the carbon nanotubes, the method comprising:
• selecting a homopolymer, blend or copolymer for the polymeric layer based on a master curve of threshold voltage as a function of charge density measured after charging at the threshold voltage for a plurality of homopolymers, copolymers and/or blends according to the desired threshold voltage of the thin film transistor.

A method for manufacturing a thin film transistor, the method comprising:

• assembling a source electrode, a drain electrode, a gate electrode and a semiconducting channel comprising a network of carbon nanotubes, such that the carbon nanotubes are electrically coupled to the source
• electrode and drain electrode and electrically insulated from, but capacitively coupled to, the gate electrode;
• and
• encapsulating the carbon nanotubes with a polymeric layer, the polymeric layer comprising a first monomeric unit and optionally a second monomeric unit, wherein the first monomeric unit, the second monomeric unit and the relative amounts thereof are selected to provide at least one target electrical property of the thin film transistor.