Title :
Transfer of GaN LEDs From Sapphire to Flexible Substrates by Laser Lift-Off and Contact Printing
Author :
Chun, Jaeyi ; Hwang, Youngkyu ; Choi, Yong-Seok ; Jeong, Tak ; Baek, Jong Hyeob ; Ko, Heung Cho ; Park, Seong-Ju
Author_Institution :
Dept. of Nanobio Mater. & Electron., Gwangju Inst. of Sci. & Technol., Gwangju, South Korea
Abstract :
We fabricate flexible GaN-based light-emitting diode (LED) systems by laser lift-off (LLO) and transfer printing methods. LLO enables transferring a whole GaN LED layer from sapphire onto a silicon handling wafer to provide a stable platform for any shape of LED. Polymer pedestal structures underneath the LEDs support efficient transfer printing of the patterned LED array from the silicon handling wafer to a flexible substrate. We demonstrate the efficacy of the technique by presenting 9 × 9 LED arrays on polyethylene terephthalate and heart-shaped LED pixels on a piece of paper with transfer yields of 92% and 79%, as well as their successful illumination.
Keywords :
III-V semiconductors; flexible electronics; gallium compounds; light emitting diodes; wide band gap semiconductors; Al2O3; GaN; LED layer; LLO; Si; contact printing; flexible GaN-based light-emitting diode systems; flexible substrate; heart-shaped LED pixels; laser lift-off; patterned LED array; polyethylene terephthalate; polymer pedestal structure; sapphire substrate; silicon handling wafer; transfer printing method; Films; Gallium nitride; Light emitting diodes; Positron emission tomography; Printing; Silicon; Substrates; Flexible light-emitting diode (LED); GaN; laser lift-off (LLO); transfer printing;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2012.2221694
