Inkjet Printing Matrix Perovskite Quantum Dot Light‐Emitting Devices

Abstract Perovskite light emitting devices have been expected to be utilized in the field of displays. In this work, a stable FA 0.3 Cs 0.7 PbBr 3 perovskite quantum dot ink with optimized octane:dodecane cosolvent is obtained by introducing a trace amount of long‐chain ligand of oleylamine (OAm) during the quantum dot purification process. A green electroluminescent matrix device with 120 pixels per inch (PPI) is realized from the ink by using an inkjet printing technique, exhibiting a luminance of 1233 cd m −2 , a peak current efficiency of 10.3 cd A −1 , and an external quantum efficiency of 2.8%. The results may suggest a possibility of making perovskite quantum dot displays by using the inkjet printing technique.