We present the photo- and electroluminescence properties of the statistical copolymer, poly[2,5-bis(dimethyloctylsiyl)-1,4-phenylenevinylene)]-co-[2,5-bis(triethoxymethoxy)-1,4-phenylenevinylene)], BDMOS-co-BTEM-PPV, designed to combine the high efficiency of BDMOS-PPV, with the ion-coordinating ability of BTEM-PPV. We find that the photoluminescence efficiency is increased to about 17%, from 8.8% for BTEM-PPV. Single-layer light-emitting diodes with calcium (aluminum) cathodes exhibit luminances up to 1300 (10) cd/m(2) with an efficiency of approximate to0.5 (0.01) cd/A. ITO/BDMOS-co-BTEM-PPV:LiTf (8 wt %)/Al. devices display behavior typical of light-emitting electrochemical cells, LECs, with efficiencies up to 0.03 cd/A. These results show that this statistical copolymer approach is successful at improving the photoluminescence efficiency, while also granting sufficient ion coordination for LEC applications.