- HAND set up one of the best laser facilities including excimer, UV, Green, IR DPSS lasers and Flash Lamp for human electronics. With outstanding light annealing system of HAND, our group also research light-material interaction, light-induced flexible electrodes, laser dopant activation for monolithic 3D integration and photo-pyrolysis for electromagnetic shield materials The use of lasers for industrial, scientific, and medical applications has received an enormous amount of attention due to the advantageous ability of precise parameter control for heat transfer. It has realized unique photothermal and photochemical reactions with various types of materials, including metal nanomaterials, ceramics, graphene, polymers, and perovskites, enabling the substantial performance improvement of human electronics.
- Our group developed Laser Lift-off(LLO) technology to provide breakthrough of inorganic-based high performance soft electronics. By using light-reacting layer and laser irradiation through transparent sacrificial substrate, high performance flexible oxide TFT, flexible piezoelectric nanogenerator and flexible memory have been transferred from bulk substrate to flexible substrates.
- Inorganic-based micro-light-emitting diodes (µLEDs) are highly anticipated for next-generation displays, but they require robust electrode materials on glass substrates to prevent delamination. To achieve this, Prof. Lee’s group developed a highly robust copper (Cu) electrode on a glass substrate using a novel flash-induced chemical and physical interlocking process, enabling the reliable operation and integration of AlGaInP thin-film vertical µLED arrays even under severe thermal and moisture stresses
- The high performance inorganic electronics for human augmentation should be developed into form-factor free devices, which can be conformally attached on arbitrary 3D surfaces such as human skins, clothes, and curved regions. However, in contrast to the outstanding achievement in active device performance, there still remains some critical bottlenecks to develop the flexible packaging technologies with reliable electrical interconnections, mechanical stabilities, and uniform power distribution under bent state. Our group developed innovative flexible packaging method using anisotropic conductive film (ACF) as an elastic and resilient packaging medium, which formed a vertical current path between the active device and electrodes through a thermo-compressive bonding process. We introduced flexible GaAs micro light-emitting diodes (µLEDs) interconnected by ACF bonding process on a plastic substrate. Additionally, we demonstrated Si-based flexible NAND flash memory via roll-based ACF packaging technology, presented in International Electron Device Meetings (IEDM, 2015), which showed reliable interconnection characteristics in various stress conditions.
- As traditional copper wires face severe data bottlenecks and power limits in the AI ans HPC era, Co-Packaged OPtics (CPO) has emerged as the definitive solution. Our laboratory specializes in advanced material processing technologies powered by precise femtosecond lasers as the core enabler for this next-generation CPO architecture. By leveraging our proprietary laser-material interaction expertise, we engineer advanced optical interconnects that seamlessly bridge semiconductor chips and optical modules, achieving unprecedented data bandwidth and energy efficiency.
[Related References]
“Janus Graphene Liquid Crystalline Fiber with Tunable Properties Enabled by Ultrafast Flash Reduction” Small, 1901529, 2019
“Flash-induced ultrafast recrystallization of perovskite for flexible light-emitting diodes” Nano Energy, 61, 236, 2019
“Flash-welded ultraflat silver nanowire network for flexible organic light-emitting diode and triboelectric tactile sensor” APL Mater. 9, 061112 , 2021
“Metastable Quantum dot for photoelectric devices via flash-induced one-step sequential self-formation” Nano Energy, 84, 105889, 2021
“Flash-induced Robust Cu electrode on Glass substrates and its application for thin-film µLED” Adv. Mater., 33, 2007186, 2021
“Flashlight-material interaction for wearable and flexible electronics” Materials Today, 51, 525, 2021
