High‐Resolution 960 × 540 and 1920 × 1080 UV Micro Light‐Emitting Diode Displays with the Application of Maskless Photolithography. Issue 7 (28th May 2021)

• Record Type: Journal Article
• Authors: Wu, Meng-Chyi; Chen, I-Ting
• Is Part Of: Advanced photonics research. Volume 2:Issue 7(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-05-28
• Subjects: 960 × 540 and 1920 × 1080 micro light-emitting diode arrays -- flip-chip bonding -- maskless photolithography -- UV micro-LED displays; Photonics -- Periodicals; 621.36505
• DOI: 10.1002/adpr.202100064
• Languages: English
• ISSNs: 2699-9293

Abstract

Abstract : Herein, active matrix 370 nm ultraviolet (UV) micro light‐emitting diode (micro‐LED) displays with full high‐definition resolution of 960 × 540 and 1920 × 1080 and high pixel densities of almost 2000 and 3200 pixels per inch (PPI), respectively, are reported. A novel self‐aligned process is used to fabricate the 1920 × 1080 micro‐LED array with the inverted trapezoidal‐shape mesa, which is different from the conventional vertical mesa for the 960 × 540 micro‐LED array. In addition, the single pixels with the diameters of 8 and 5 μm on the 960 × 540 and 1920 × 1080 microarrays exhibit excellent characteristics, including the low forward voltages of 3.35 and 3.29 V at the currents of 17.4 and 4.4 μA, extremely low leakage currents of 19.5 and 9.4 pA at −10 V, and high light output powers of 150 and 71 μW at 1 mA, respectively. Through flip‐chip bonding technology, the 1920 × 1080 micro‐LED display has a higher light output power of 2.6 mW than the 960 × 540 micro‐LED display of 1.8 mW at the same driving current of 100 mA and voltage of 5 V. Both the UV micro‐LED displays demonstrate the delivery of graphic images and simple pattern‐programmable maskless photolithography on resist‐coated wafers. Abstract : Herein, 370 nm 1920 × 1080 matrix‐addressable micro light‐emitting diode displays with 5 μm pixel size, 8 μm pitch, and 3200 pixels per inch. within 0.69 inch diagonal length are reported. The micro‐LED displays are connected to a flexible printed circuit assembly (FPCA) operated at 250 mA and 2.7 V.