Charge-transfer　states　have　been　observed　extensively　in　heterojunctions　of　organic　semiconductors,　which　are　also　referred　to　as　exciplexes　in　polymer　blends.　Such　mechanisms　have　been　well　understood　in　the　conventional　material　systems.　However,　electromer　states　may　be　produced　only　in　some　polymeric　molecules　with　folded　chains.　We　report　here　the　interaction　between　exciplex　and　electromer　states,　which　facilitates　the　formation　of　a　new　electrically　excited　state　that　we　define　as　a　secondary　exciplex.　This　is　an　indirect　process　understood　as　an　electromer-mediated　heterojunction.　We　discovered　such　an　optoelectronic　mechanism　in　the　blend　film　of　poly(9,9＇-dioctylfluorene-co-bis-N,N＇-(4-butylphenyl)-bis-N,N＇-phenyl,4-phenylene-diamine)　(PFB)　and　poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt(benzo[2,1,3]thiadiazol-4,8-diyl)]　(F8BT).　Four　emission　bands　can　be　resolved　from　the　electroluminescence　spectrum,　including　those　based　on　the　excitons,　the　electromers,　and　the　primary　and　secondary　exciplexes.　The　whole　electroluminescence　spectrum　thus　extends　from　the　green　(500　nm)　to　the　near-infrared　(900　nm)　with　a　full　bandwidth　of　400　nm.　These　new　discoveries　with　the　conventional　light-emitting　polymers　are　important　not　only　for　polymeric　optoelectronics,　but　also　for　the　development　of　broadband　light-emitting　devices.