Efficient and almost pure white-light emission is obtained by combining singlet and triplet emission in a single-polymer device. The polymers used in this work include a benzothiadiazole group attached to a fluorene backbone and an iridium complex attached to the side chain (see figure). White-light emission with CIE color coordinates of (0.32, 0.44) and a luminance efficiency of 6.1 cd A(-1) is obtained.