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Quantum dot color converters (QDCCs) are a leading technology for enhancing the gamut and efficiency of displays, notably in QD‐OLED TVs and monitors. However, cadmium‐free QDs require thick layers for effective color conversion. Our novel inorganic photoresist densely packs InP QDs, achieving over 60% PLQY and optical density of 1 at less than 10 µm thickness, advancing QDCCs for high‐performance microLED displays. Patterning of 5 µm pixels with high fidelity is also demonstrated. 

All-inorganic nanocrystals (NCs) are of great importance in a range of electronic devices. However, current all-inorganic NCs suffer from limitations in their optical properties, such as low fluorescence efficiencies. Here, we develop a general surface treatment strategy to obtain intensely luminescent all-inorganic NCs (ILANs) by using designed metal salts with noncoordinating anions that play a dual role in the surface treatment process: (i) removing the original organic ligands and (ii) binding to unpassivated Lewis basic sites to preserve the photoluminescent (PL) properties of the NCs. The absolute photoluminescence quantum yields (PLQYs) of red-emitting CdSe/ZnS NCs, green-emitting CdSe/CdZnSeS/ZnS NCs and blue-emitting CdZnS/ZnS NCs in polar solvents are 97%, 80% and 72%, respectively. Further study reveals that the passivated Lewis basic sites of ILANs by metal cations boost the efficiency of radiative recombination of electron-hole pairs. While the passivation of Lewis basic sites leads to a high PLQY of ILANs, the exposed Lewis acidic sites provide the possibility for in situ tuning of the functions of NCs, creating opportunities for direct optical patterning of functional NCs with high resolution. 

We demonstrate a scalable fabrication method for microLED displays using photopatternable InP-based QDs. Using photosensitive ligands, we demonstrate pixel resolutions of 10 μm with EQE of >40% in <10 μm thickness. Accelerated reliability is measured and modeled to calculate an expected lifetime of >10k hours for direct-view microLED operating conditions. 

Quantum Dot downconverters will enable high-resolution, bright, and wide color gamut displays for all display formats. We have developed a method to directly photopattern densely packed InP/ZnS Quantum Dots that achieve an optical density of 2 at sub 10 μm thicknesses while preserving the photoluminescent quantum yield. 

Quantum Dot downconverters can provide a scalable solution to tri‐color high‐resolution microLED and OLED displays by converting monochrome displays using photopatternable red and green QDs. Using internal measurements collected at NanoPattern Technologies, Inc. we model and discuss the practical wall plug efficiencies for downconverted InGaN blue microLED displays. In the range of 5 μm pixel sizes, using uncorrected 65 % film PLQY, the downconverted InGaN red emitter achieves a comparable external quantum efficiency compared to a direct red emitting AlInGaP when compared at practical current densities for microLED drivers. 

Quantum Dot downconverters will enable high‐resolution, bright, and wide color gamut displays for all display formats. We have developed a method to directly photopattern densely packed InP/ZnS Quantum Dots that achieve an optical density of 2 at sub 10 µm thicknesses while preserving high photoluminescence quantum yield.