Publications

Energy Materials Laboratory

Publications

Controlled Fracture-Based Micropatterning of Ruddlesden–Popper Halide Perovskite for Ultra High-Density Arrays of Micro Light Emitting Diodes
Authors
Sunggun Yoon, Joonyun Kim, Young Ho Chu, Jinu Park, Ki-Tae Park, Kyung Tak Yoon, Nakyung Kim, Seoyeon Park, Yunna Kim, Kijoon Bang, Byungha Shin, Yun Seog Lee
Journal
Advanced Functional Materials
Vol
34
Page
2403151
Year
2024

Quasi-2D Ruddlesden–Popper perovskite (RPP) have surfaced as a promising candidate for light emitting diodes (LEDs) due to its outstanding optoelectronic properties. However, a reliable approach for patterning RPPs remains elusive due to the use of polar solvents in lithographic processes, which can damage the RPP. Here, a reliable and damage-free dry micropatterning method of RPPs is reported, which also offers a cost/time advantage compared to conventional patterning methods. The sharp edges of high aspect ratio silicon micropillars are used to cut RPPs to a pre-defined shape and then the cut RPPs are delaminated to obtain a patterned array of RPPs. The resultant patterned array exhibits no sign of degradation or discernable difference between adjacent pixels, achieving a ≈100% yield. The obtained array is utilized to fabricate a pixelated LED where a sharp electroluminescence (EL) spectrum peaking at 410 nm with full-width-at-half-maximum (FWHM) of 10 nm is observed. The pixelated devices demonstrate the potential to suppress EQE drops as the pixel size decreases, attributed to both the damage-free micropatterning process and the defect tolerance of RPPs. Moreover, further improvements of the patterning method are demonstrated to avoid parasitic emission and suggest a promising strategy to fabricate pixel-accessible micro-LEDs.