The effects of temperature on the formation and stability of bipolarons in conjugated polymers Yan Meng, Guang-jie Guo, Ya-dong Wang, Yin-feng Li and Zhong An Eur. Phys. J. B, 90 4 (2017) 72 Published online: 12 April 2017 DOI: 10.1140/epjb/e2017-80018-7