Bipolarons in Organic Electroluminescence

We investigate the bipolaron channel B⁺⁺ +B^--→BX. The dynamical evolutions and transition probabilities of this bipolaron luminescence channel are studied. It is found that this channel avoids the triplet and is able to enhance the efficiency. We suggest that choosing certain polymers and injection structures, in which B is easily formed, can improve the luminescence efficiency. It is believed that these results will motivate further experimental studies about the function of bipolarons in electroluminescence.