Semiconducting polymers are researched as alternatives to inorganic materials for use in electronic devices, such as solar cells or organic light-emitting diodes. Polymers are processable in solution, allowing for manufacturing of devices using cheap printing technology. Further, organic materials can be made biodegradable, and are made from inexpensive starting materials. Many polymers also conduct ions, a property which is used in devices such as the light-emitting electrochemical cell (LEC). An LEC is made from an organic semiconductor with mobile ions, between two electrodes. Upon operation, ions migrate in the polymer under applied bias, and in the region where positive and negative charges combine, light is emitted. Several aspects of the function of LECs are poorly understood, and we will use neutron reflectometry to monitor ion (re)distribution in LECs under operation.