An official website of the United States government
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.
more »
« less
This content will become publicly available on June 1, 2026
67‐1: Invited Paper: High Optical Density, High Efficiency Quantum Dot Photoresist for MicroLED Applications
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.
more »
« less
- Award ID(s):
- 2052728
- PAR ID:
- 10656269
- Publisher / Repository:
- The Society for Information Display
- Date Published:
- Journal Name:
- SID Symposium Digest of Technical Papers
- Volume:
- 56
- Issue:
- 1
- ISSN:
- 0097-966X
- Page Range / eLocation ID:
- 907 to 909
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
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.more » « less
-
We report a photolithography‐based technology for patterning quantum dot color converters for micro‐LED displays. A patterning resolution of ~1 µm is achieved. The method can be applied to any color converter materials. Integration of perovskite quantum dots and CdSe/ZnS quantum dots is demonstrated to show the versatility of the technology.more » « less
-
Abstract Precise patterning of quantum dot (QD) layers is an important prerequisite for fabricating QD light‐emitting diode (QLED) displays and other optoelectronic devices. However, conventional patterning methods cannot simultaneously meet the stringent requirements of resolution, throughput, and uniformity of the pattern profile while maintaining a high photoluminescence quantum yield (PLQY) of the patterned QD layers. Here, a specially designed nanocrystal ink is introduced, “photopatternable emissive nanocrystals” (PENs), which satisfies these requirements. Photoacid generators in the PEN inks allow photoresist‐free, high‐resolution optical patterning of QDs through photochemical reactions and in situ ligand exchange in QD films. Various fluorescence and electroluminescence patterns with a feature size down to ≈1.5 µm are demonstrated using red, green, and blue PEN inks. The patterned QD films maintain ≈75% of original PLQY and the electroluminescence characteristics of the patterned QLEDs are comparable to thopse of non‐patterned control devices. The patterning mechanism is elucidated by in‐depth investigation of the photochemical transformations of the photoacid generators and changes in the optical properties of the QDs at each patterning step. This advanced patterning method provides a new way for additive manufacturing of integrated optoelectronic devices using colloidal QDs.more » « less
-
A universal method of micro-patterning thin quantum dot films is highly desired by industry to enable integration of quantum dot materials with optoelectronic devices. Many of the methods reported so far, including specially engineered photoresist or ink-jet printing, are either of poor yield, resolution limited, difficult to scale for mass production, overly expensive or sacrifice some optical quality of the quantum dots. In our previous work, we presented a dry photolithographic lift-off method for pixelization of solution-processed materials and demonstrated its application in patterning perovskite quantum dot pixels, 10 µm in diameter, to construct a static micro-display. In this report, we present further development of this method, and demonstrate high-resolution patterning (~1 µm diameter), full-scale processing on 100 mm wafer, and multi-color integration of two different varieties of quantum dots. Perovskite and cadmium-selenide quantum dots were adopted for the experimentation, but the method can be applied to other types of solution-processed materials. We also show the viability of this method for constructing high-resolution micro-arrays of quantum dot color-convertors by fabricating patterned films directly on top of a blue gallium-nitride LED substrate. The green perovskite quantum dots used for fabrication are synthesized and prepared by our research group via room temperature ligand-assisted reprecipitation method, and these synthesized quantum dots have a photoluminescent quantum yield of 93.6% and full-width half-maximum emission linewidth less than 20 nm. Our results demonstrate the viability of this method for use in scalable manufacturing of high-resolution micro-displays.more » « less
