Ink-Jet Printed Stable Full-Color Perovskite and Quantum Rod Color Filter

Photoluminescence color filter (PLCF) array using quantum color converters is recently a strong candidate to replace traditional absorptive CF in various display applications. PLCF displays are expected to have higher efficiency and wider color gamut. Ink-jet printing is a versatile and low-cost method to pattern color converting films, but uniformity problem is to be concerned. To utilize perovskite nanoparticles (PNP) and low dimension semiconductor material, maintaining good photoluminescence (PL) properties in the processing and long-term stability is challenging. In our work, we use a porous polymer film (PF) as the ink jet printing template. Capillary effect of the sub-micron pores in the PF promotes uniform coffee-ring free printing with reduced size (<50 μm). Without using any mask or bank structures, green PNP and red Quantum Rod (QR) arrays can be printed with high quality. The PF CF is endowed with good PL stability for more than 80 days. In terms of device application, ambient contrast ratio become problematic considering the ambient light excitation of color converters. We adapted bottom CF structure for LCD to solve this problem. A LCD equipped with a printed full-color PNP-QR PF CF was demonstrated. The color gamut of the design can reach 96.9% BT.2020.