Flexible Quantum-Dot Color-Conversion Layer Based on Microfluidics for Full-Color Micro-LEDs

Abstract

In this article, red and green perovskite quantum dots are incorporated into the pixels of a flexible color-conversion layer assembly using microfluidics. The flexible color-conversion layer is then integrated with a blue micro-LED to realize a full-color display with a pixel pitch of 200 μm. Perovskite quantum dots feature a high quantum yield, a tunable wavelength, and high stability. The flexible color-conversion layer using perovskite quantum dots shows good luminous and display performance under different bending conditions; is easy to manufacture, economical, and applicable; and has important potential applications in the development of flexible micro-displays.

Progress in Color Conversion Technology for Micro‐LED

“…These technologies have played an important role in the preparation of high-performance and low-cost flexible wearable displays in the future. [97][98][99][100][101][102] In 2020, S. Lee et al proposed a method to directly generate a GaN array on a sapphire substrate without a plasma etching process. In this method, discrete core-shell Micro-LED arrays were grown on sapphire nanofilm arrays with [4] Copyright 2013, The Optical Society.…”

“…These technologies have played an important role in the preparation of high‐performance and low‐cost flexible wearable displays in the future. [ 97–102 ]…”

Current Confinement Effect on the Performance of Blue Light Micro-LEDs with 10 μm Dimension

“…Coating QDs on substrates can be achieved through photolithography, transfer printing, and inkjet printing. − The smallest RGB subpixel pattern resolutions achieved with these QD fabrications are 14 μm × 14 μm, 5 μm × 39 μm, and 50 μm × 50 μm . For these applications, a high-efficiency blue light source with an InGaN/GaN structure is commonly used to excite the material and achieve a full-color display. , Researchers have explored various methods to passivate small-sized μLEDs, including changing the material of the passivation layer − or growing denser films using the ALD process. − Passivation of sidewalls using chemical solutions has also been proposed to reduce leakage current in small-sized μLEDs. − While these methods can improve device performance, they also increase process costs.…”

Microfluidic static droplet generated quantum dot arrays as color conversion layers for full-color micro-LED displays

“…This resulted in a crosstalk effect at the microbridge junction of adjacent pixels of the same color, which affected the performance of the device. 28 In this paper, we propose a simple and intact method to fabricate QDCCLs that exploits microuidic static droplet array (SDA) technology. As a typical representative of droplet micro-uidics, SDA technology can generate, transport, immobilize, fuse, and store micro-droplets 29,30 ranging from 1 mm to 1 mm, [31][32][33][34][35] which is comparable to the pixel size of micro-LEDs.…”

“…This resulted in a crosstalk effect at the microbridge junction of adjacent pixels of the same color, which affected the performance of the device. 28 …”