High-brightness Perovskite Light-emitting Diodes Using a Printable Silver Micro-flake Contact

Achieving efficient devices while maintaining a high fabrication yield is a key challenge in the fabrication of solution-processed, perovskite-based light-emitting diodes (PeLEDs). In this respect, pinholes in the solution-processed perovskite layers are a major obstacle. These are usually mitigated using organic electron-conducting planarization layers. However, these organic interlayers are unstable under applied bias in air, and suffer from limited charge-carrier mobility. In this work, we present a high brightness p-i-n PeLED based on a novel blade-coated silver micro-flake (SMF) rear electrode, which allows for a low-cost and high performance nanocrystalline ZnO inorganic electron transporting layer to be used. This novel SMF contact is crucial for achieving high performance as it prevents the electrical shorting suffered when standard thermally evaporated silver rear contacts are used. The fabricated PeLEDs exhibit an excellent maximum luminance of 98000 cd/m2, a maximum current efficiency of 22.3 c...