| abstract |
A composition comprising an organic semiconductor material and a triplet acceptor material of formula (I) having a lower triplet energy level than the triplet energy level of the organic semiconductor material, wherein each Ar is an optionally substituted aryl or heteroaryl group, n is 1-3, m is 1 Is -5, q is 0 or 1, each R 3 is H or a substituent and each R 4 is H or a substituent. When R 4 is not H, R 4 and (Ar) m which are bonded to the same carbon atom may be bonded by a direct bond or a divalent group. When m or n is at least 2, adjacent Ar groups may be bonded through a divalent group. When q = 0, R 3 is not H and is bound to (Ar) n by a direct bond or divalent group. |