Langmuir–Schaeffer Monolayers of Colloidal Nanocrystals for Cost‐Efficient Quantum Dot Light‐Emitting Diodes

: Quantum dot (QD) LEDs of high color purity, and low turn-on voltage and leakage current are prepared using a solvent free method. First, a monolayer of QDs is formed at the air/water interface, which is then transferred with a PDMS stamp onto the device. The method is applicable to large substrates and reduces materials consumption as compared to other deposition techniques.