Abstract:The injection of charge carriers from the electron/hole injection or transport layers in polymer light-emitting diodes potentially increases the device efficiency not by changing of charge intensity but by lattice distortion variation and quasi-particle interactions. From the low-dimensional condensed matter physics perspective, a valid mechanism is proposed to bring a type of novel channels that, under a proper external electric field, transition-forbidden triplet excitons are transformed and partially charged by charge carriers (polarons/bipolarons), thus are able to emit light and to enhance fluorescence greatly.