Soo‐Yeon Lee

Brain-inspired neuromorphic computing emulates the biological functions of the human brain to achieve highly intensive data processing with low power consumption. In particular, spiking neural networks (SNNs) that consist of artificial synapses can process spatiotemporal information while enabling energy-efficient neuromorphic computations. Artificial synapses are a key element of sophisticated neuromorphic hardware, so a significant amount of research has been conducted to develop various mater

Abstract Brain‐inspired neuromorphic computing has drawn significant attraction as a promising technology beyond von Neumann architecture by using the parallel structure of synapses and neurons. Various artificial synapse configurations and materials have been proposed to emulate synaptic behaviors for human brain functions such as memorizing, learning, and visual processing. Especially, the memory type indium‐gallium‐zinc‐oxide (IGZO) synaptic transistor adopting a charge trapping layer (CTL) h

We present comprehensive studies on ZnON thin films deposited by radio-frequency (RF) magnetron sputtering using a ZnO target under various nitrogen plasma conditions. A ZnON thin film grown under the highest nitrogen partial flow rate exhibits the lowest optical bandgap of 1.84 eV, excellent stability upon air exposure, an amorphous/nanocrystalline structure, and the strongest stoichiometric Zn3N2 chemical states. The highest field-effect mobility of 4.28 cm2 V–1 s–1, the largest responsivity,

We investigated the hysteresis and off-current (I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</sub> ) of amorphous In-Ga-Zn oxide thin-film transistors illuminated by 400 nm light at various intensities. Both hysteresis and I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</sub> are induced by the ionized oxygen vacancy (Vo <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="htt

We investigated the reliability of oxide TFTs under negative gate bias stress combined with various intensities of light having a wavelength of 400 nm. Light illumination caused a considerable <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> shift toward negative direction, as reported in previous works. However, the trapping probability of a s

Neuromorphic computing emulating the human brain offers a promising alternative to the Von Neumann architecture. Developing artificial synapses is essential for implementing hardware neuromorphic systems. Indium-gallium-zinc oxide (IGZO)-based synaptic transistors using charge trapping have advantages, such as low-temperature process and complementary metal-oxide-semiconductor compatibility. However, these devices face challenges of low charge de-trapping efficiency and insufficient retention. H

We have proposed a new AMOLED pixel design compensating IR drop besides threshold voltage (Vth) variation of LTPS TFTs without any additional signal. The SPICE simulation results show that the proposed pixel, which consists of 7 PMOS TFTs and 1 capacitor, successfully compensates not only Vth variation but also IR drop. Vth of the driving TFTs are detected and data voltage can be memorized when PMOS only inverter has high input voltage.

We propose that the post-deposition oxidation of the IGZO surface is essential for improving the interface quality, with Al₂O₃ prepared by atomic layer deposition (ALD) employing a common metal precursor trimethylaluminum (TMA). Here, the ALD-Al₂O₃ process was conducted using H₂O as an oxidant at a substrate temperature of 150 °C after IGZO deposition. The depth-resolved X-ray photoelectron spectroscopy (XPS) and transmission electron micros

Abstract We have proposed a new active organic light‐emitting diode display (AMOLED) pixel design, which is suitable for the simultaneous emission driving high definition AMOLED. In the previous work, the pixel structure could be simplified with the simultaneous emission driving compared to the widely used progressive emission driving. However, the flickering was observed. The proposed pixel circuit can suppress the flickering because 120 Hz operation is possible. The SPICE simulation results sh

This letter presents a multiple sound localization method for non-stationary speech sources in reverberant environments. Although zero-crossing-based interaural time differences (ITDs) were robust to diffuse noise and energy-based onset detection tackled reverberant speech , the onset detection method was sensitive to parameters. The proposed method employs echo-free onset detection , and this letter adds reverberation time estimation to obtain accurate echoes and signal-to-noise ratio estimatio