Polymer, polymer composition and organic light-emitting device

A polymer comprising conjugating repeat units, non-conjugating repeat units and amine repeat units in a backbone of the polymer wherein:

• the conjugating repeat units provide at least one conjugation path between repeat units linked thereto;
• the non-conjugating repeat units comprise an at least partially saturated ring comprising at least one ring atom that breaks any conjugation path between repeat units linked to the non-conjugating repeat unit such that a highest occupied molecular orbital level of the polymer is further from vacuum level by at least 0.1 eV and/or a lowest unoccupied molecular orbital level of the polymer is closer to vacuum level by at least 0.1 eV as compared to a polymer in which the non-conjugating repeat units are absent;
• and
• the amine repeat units comprise repeat units of formula (V):
• wherein Ar1 and Ar2 in each occurrence are independently selected from optionally substituted aryl or heteroaryl groups, n is greater than or equal to 1, R is H or a substituent, p and q are each independently 1, 2 or 3, and any of the aryl or heteroaryl groups of formula (V) may be linked by a direct bond or a divalent linking group.

A method of tuning the bandgap of a polymer comprising conjugating repeat units and non-conjugating repeat units in a backbone of the polymer wherein:

• the conjugating repeat units provide at least one conjugation path between repeat units linked thereto;
• and
• the non-conjugating repeat units comprise an at least partially saturated ring having ring atoms that break any conjugation path between repeat units linked to the non-conjugating repeat unit,
• the method comprising the step of determining a minimum target bandgap of the polymer that is at least 0.1 eV larger than the bandgap of a polymer in which the non-conjugating repeat units are absent, and polymerising a polymerisation mixture comprising a first monomer comprising a non-conjugating unit and a second monomer comprising a conjugating unit, the ratio of the first and second monomers being selected so as to form a polymer having the minimum target bandgap.