On the way to wafer-level quantum dot light-emitting diodes

Solution-processed quantum dot light-emitting diodes (QDLEDs) have recently paved the way for low-cost and color-saturated displays. Indeed, quantum dots (QDs) have the appealing property of emitting at a tunable wavelength determined by their chemical composition and diameter. Therefore, QDLED electroluminescent spectra exhibit a narrow bandwidth (FWHM at approximately 30 nm) and QD-based displays offer high color purity and saturation. Moreover, QDs may be deposited by spin coating, inkjet printing, and stamping, methods already implemented for polymer LEDs at the wafer level. We report the optimization steps and performances of our recent developed devices emitting in the visible range. We present pros and cons relative to each method of QD deposition and develop a strategy for realizing wafer-level QDLEDs.