Single layer electroluminescent (EL) devices based on soluble p type polymer PDDOPV doped by n type soluble polymer PPQ are successfully fabricated.Comparing with single layer devices of pure PDDOPV,the turn on voltage of doped single layer devices is drop from 4.5 V to 2.6 V at the same applied voltage,the current is higher but still at the same order of magnitude,the brightness and luminescent efficiency are both enhanced more than one order of magnitude.At 10 V,the current,brightness and luminescent e...