Transparent light-emitting electrochemical cells with acid treated multi-wall carbon nanotubes as a top electrode

Halide perovskite light-emitting electrochemical cells (LEC) are color-tunable, efficient, simple, and low-cost single-layer devices, which can be designed in semitransparent architectures for various lightening and display. However, development of highly transparent and conductive electrodes for these devices is a challenging task, requiring not only optimization of the electrode material parameters, but also stable performance without chemical reactions at interfaces. Here we employ multi-walled carbon nanotubes with substantially improved optical and transport properties after their additional chemical processing for efficient semitransparent perovskite LEC. In particular, we develop single-layer perovskite-based LECs with transparency 56%, brightness up to 1625 cd/m2 and maximum current efficiency 3.6 cd/A. We believe that our low-cost and efficient devices would be suitable for semitransparent display technologies.