A Study of Elastic Light-Emitting Diode Based on CsPbBr3 Perovskite Film Crystallized on a Gallium Phosphide Nanowires Array

Recently, there has been rapid progress in technologies for creating flexible and stretchable optoelectronic devices. A promising material in terms of its fundamental properties is the inorganic halide perovskite CsPbBr3, whose electroluminescence brightness can reach 45 000 cd/m2. However, the most common thin-film technology for fabricating perovskite-based devices fails to address several key challenges, such as ensuring environmental stability of the perovskite, creating stretch-resistant contacts, and enabling efficient carrier injection into the electroluminescent layer. To address these issues, the authors developed a new device architecture based on a distributed electrode that incorporates an array of whisker nanocrystals embedded in the light-emitting layer, thereby solving the fundamental problem of the short carrier lifetime in CsPbBr3. The device is encapsulated in a special silicone polymer—a transparent, inert, flexible, and stretchable matrix that protects the CsPbBr3 perovskite from environmental exposure and preserves the orientation of the whisker nanocrystal arrays. Ninety-percent transparent single-walled carbon nanotubes, which possess high tensile strength and low electrical resistance, were used as the electrode responsible for lateral carrier transport. As a result, a flexible device with high electroluminescence efficiency was achieved.