High-resolution, full-color quantum dot light-emitting diode display fabricated via photolithography approach

Displays play an extremely important role in modern information society, which creates a never-ending demand for the new and better products and technologies. The latest requirements for novel display technologies focus on high resolution and high color gamut. Among emerging technologies that include organic light-emitting diode (OLED), micro light-emitting diode (micro-LED), quantum dot light-emitting diode (QLED), laser display, holographic display and others, QLED is promising owing to its intrinsic high color gamut and the possibility to achieve high resolution with photolithography approach. However, previously demonstrated photolithography techniques suffer from reduced device performance and color impurities in subpixels from the process. In this study, we demonstrated a sacrificial layer assisted patterning (SLAP) approach, which can be applied in conjunction with photolithography to fabricate high-resolution, full-color quantum dot (QD) patterns. In this approach, the negative photoresist (PR) and sacrificial layer (SL) were utilized to determine the pixels for QD deposition, while at the same time the SL helps protect the QD layer and keep it intact (named PR-SL approach). To prove this method's viability for QLED display manufacture, a 500-ppi, full-color passive matrix (PM)-QLED prototype was fabricated via this process. Results show that there were no color impurities in the subpixels, and the PM-QLED has a high color gamut of 114% National Television Standards Committee (NTSC). To the best of our knowledge, this is the first full-color QLED prototype with such a high resolution. We anticipate that this innovative patterning technique will open a new horizon for future display technologies and may lead to a disruptive and innovative change in display industry.