Blade-coated perovskite nanoplatelets polymer composite for sky-blue light-emitting diodes

Abstract

Colloidal perovskite nanoplatelets (NPLs) have shown promises for tackling the blue light-emitting diode challenges based on their tunable band gap and high photoluminescence efficiencies. However, high quality and large area dense NPLs films have proven very hard to prepare because of its chemical and physical fragility during the liquid phase deposition Herein, we report a perovskite-polymer composite film deposition strategy with fine morphology engineering obtained with the blade coating method. The effects on the film quality of polymer type, solution concentration, compounding ratio and film thickness are systematically investigated. We found that a relatively high-concentration suspension with an optimized NPLs to polymer ratio of 1:2 is crucial for the suppression of phase separation and arriving at a uniform film. Finally, sky-blue NPLs-based perovskite light-emitting diodes were fabricated by blade coating showing EQE of 0.12% on a device area of 16 mm².