Understanding and controlling the dynamic p-n junction for improved light-emitting electrochemical cells

The light-emitting electrochemical cell (LEC) can emit from large and flexible “surfaces” and be fabricated with sustainable and cost-efficient methods akin to how newspapers are printed.

The initial LEC operation constitutes electrochemical p- and n-type doping, which results in the formation of a light-emitting “p-n junction” doping structure.

We have recently shown that the detailed structure of this dynamic p-n junction strongly affects the LEC performance, and used early rudimentary insights for the realization of LECs with record-high efficiency.In the proposed project, we will perform well motivated optical, electronic, electrochemical and simulation experiments to establish up-to-now lacking fundamental understanding of the electrochemical doping process.

The acquired information will be utilized to establish guidelines for how the p-n junction doping structure can be controlled, with two distinct deliverables being the positioning of the junction region in the center of the active material and the increase of the electron and hole mobility in the undoped junction region.

Our goal is that this new information will allow us to rationally design efficient and bright LECs with long-term stability.

The emergence of such high-performance, sustainable and easily tunable LEC sheets promise in the short term to enable novel applications of light emission in medtech, and in the longer term to pave the way for a thin, conformable and truly “green” light source.