https://scholar.dgist.ac.kr/handle/20.500.11750/121 Sat, 04 Apr 2026 11:37:37 GMT 2026-04-04T11:37:37Z https://scholar.dgist.ac.kr/handle/20.500.11750/59972 Title: Hole Current Enhancement Using W1-x Cr x Se2 Alloy Interface for p-Type WSe2 FETs Author(s): Sim, Young-Jun; Kim, Junil; Lee, Jieun; Lee, Byeongmoon; Jang, Jae Eun; Kwon, Hyuk-Jun Abstract: Two-dimensional (2D) transition-metal dichalcogenides (TMDs) have emerged as promising candidates for next-generation semiconductor devices. Among TMDs, tungsten diselenide (WSe2) is regarded as an ideal material for p-type field-effect transistors (FETs). However, the realization of high-performance p-type devices remains limited due to undesired ambipolar behavior and high contact resistance. These challenges originate from Fermi level pinning (FLP) caused during conventional deposition processes. Although van der Waals (vdW) contacts have been introduced to overcome FLP, their implementation faces difficulties due to contamination-induced degradation and limitations in CMOS process compatibility. In this study, we demonstrate a scalable approach for p-type contact via the W1-xCrxSe2 alloy interface. It has been reported that Cr incorporation reduces the bandgap of WSe2, while CrxSey exhibits p-type semimetal properties. Leveraging these properties, thermal annealing of Cr contacts enables the formation of WSe2/W1-xCrxSe2/Cr layers at the contact region. This interfacial alloy effectively suppresses FLP, eliminates undesirable ambipolar behavior, and enhances hole injection. The resulting devices achieve a Schottky barrier height as low as 61.1 meV and reduce contact resistance by approximately 3 orders of magnitude. Consequently, W1-xCrxSe2 alloy interface contact WSe2 FETs exhibit robust p-type performance with an average on/off current ratio of 2.19 x 10(8) across 20 devices. These findings present a practical and scalable strategy for engineering low-resistance p-type contacts in WSe2, providing an important step toward the integration of TMD-based complementary logic in future scaled CMOS technologies. Sun, 30 Nov 2025 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/59972 2025-11-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59971 Title: Heterojunction Wide-Bandgap Amorphous Metal Oxide High-Voltage Thin-Film Transistors with High Driving Current and Low Process Temperature Author(s): Lee, Jungha; Lee, Junhee; Kim, Duhee; Kwon, Hyuk-Jun; Jang, Jae Eun; Kang, Hongki Abstract: The implementation of high-voltage (HV) applications in monolithic integration has led to increased demand for wide-bandgap high-voltage thin-film transistors (HVTFTs) to solve voltage mismatch problems between HV devices and complementary metal oxide semiconductor (CMOS) integrated circuits. However, typical HVTFTs possess several limitations, including low driving current due to the drain offset structure and high process temperature (>300 degrees C), limiting high-frequency switching operation and flexible substrate compatibility, thus impeding their application in flexible and wearable HV electronics. This study presents heterojunction wide-bandgap channel-based HVTFTs fabricated using amorphous indium tin zinc oxide (a-ITZO) and indium gallium zinc oxide (a-IGZO) to overcome the limitations of the current HVTFTs. Owing to the heterojunction channel layer, we achieved a much higher driving current of >0.37 mA/mm (I-D/W) at V-GS = 210 V and V-DS = 5 V with a flexible-electronics-compatible channel layer annealing temperature (150 degrees C), indicating that the TFTs can be even applied in HV flexible/wearable electronics. Therefore, ITZO/IGZO TFTs can withstand considerably higher power than single-layer IGZO HVTFTs, while exhibiting similar HV breakdown characteristics. Additionally, the ITZO/IGZO HVTFTs demonstrate superior electrical stability under high-voltage-bias conditions compared to conventional IGZO HVTFTs. Thus, heterojunction amorphous metal oxide TFTs are suitable for fast switching flexible HV electronic systems while gate-controlled by CMOS technologies. Sun, 30 Nov 2025 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/59971 2025-11-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59969 Title: Study of active-matrix high-power transistor design for electrical stimulation Author(s): Kim, Joonghyun; Lee, Jeonghun; Chae, Ji Won; Kim, Dongsu; Pyo, Goeun; Heo, Su Jin; Jang, Jeonggyun; Park, Heechang; Kang, Hongki; Kwon, Hyuk-Jun; Jang, Jae Eun Abstract: Among various methods for generating artificial tactile sensations, a haptic device that employs electrical stimulation has attracted significant attention due to its high potential for realizing hyper-realistic touch. Considering the high skin impedance and the dense population of tactile receptors in the fingers, achieving a high-resolution electrode design with high-power operation and a flexible form-factor is required. In this study, an electrical stimulation haptic device employing a high-power transistor with an active matrix (AM) design on a flexible substrate was demonstrated. We optimized parameters for the thin-film transistor (TFT) employing Indium-Gallium-Zinc-Oxide (IGZO) to sustain biphasic signal conditions as well as high power driving for electrical stimulation and its compatibility with low-process temperature for flexible form-factor. In order to secure the operating range of the driving TFT, the skin resistance value was measured based on the actual electrical stimulation waveform and confirmed to be 20-30 k Omega on average. The resulting device achieved a spatial resolution of 64 channels within a 1 cm(2) area. To achieve high drain current of TFT, a comb-shaped design of source and drain was suggested. The TFT can transfer high biphasic voltage (similar to +/- 50 V) with high simulation current (>10 mA). Therefore, the electrical stimulation device with high electrode density can supply sufficient power with wide bipolar stimulus signal swings stably for finger skin stimulation and various human interface devices. Sat, 28 Feb 2026 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/59969 2026-02-28T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59222 Title: Stable olfactory receptor activation across odor complexity Author(s): Kim, Minseok; Lee, Jeongyoon; Park, Inah; Kim, Jihoon; Lee, Keunsoon; So, Jinhyun; Choi, Ji-Woong; Jang, Jae Eun; Kwon, Hyuk-Jun; Moon, Cheil; Choe, Han Kyoung Abstract: Mechanisms underlying single odorant activation of specific olfactory receptors are well understood. However, how the olfactory system processes complex odor mixtures at the receptor level remains unclear. This study examined olfactory receptor activation patterns across odor complexities using phosphoTRAP analysis. For most mixtures, receptor activation patterns closely matched the linear sum of individual component responses. However, distinct receptor sets display non-linear responses unexplained by linear models. Mixture responses were generally located between component responses and often aligned with linear predictions, though some deviations indicated non-linear interactions. Total activated receptors remained relatively constant regardless of odor complexity, suggesting efficient coding that prevented receptor saturation as odorant components increased. These findings provide receptor-level evidence that the olfactory system encodes complex odors primarily through linear integration of receptor activity, with added specificity from non-linear responses in limited receptors, advancing understanding of how the olfactory system normalizes receptor activation in response to natural odors. Fri, 31 Oct 2025 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/59222 2025-10-31T15:00:00Z