Electrochemical control of amplified spontaneous emission in conjugated polymers

► We study the amplified spontaneous emission (ASE) in a conjugated polymer. ► Low threshold intensity for amplified spontaneous emission is reported. ► The switch from photoluminescence to ASE can be electrochemically controlled. ► The oxidation level of PEDOT:PSS controls the switch. ► The switch can also be observed in aqueous salt.