Article
Nanoscience & Nanotechnology
Zhaohua Zhu, Yang Li, Zhiqiang Guan, Yan Wu, Zixin Zeng, Sai-Wing Tsang, Shihao Liu, Xiao Huang, Chun-Sing Lee
Summary: By inserting a CsAc layer between the HTL and the hole-dominant perovskite layer, the performance of PeLEDs can be improved by suppressing exciton quenching and enhancing the photophysical properties of the perovskite film.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Shisir Devkota, Hirandeep Kuchoor, Kendall Dawkins, Rabin Pokharel, Mehul Parakh, Jia Li, Shanthi Iyer
Summary: In this study, a systematic design of growth experiments and subsequent characterization of GaAsSb heterostructure axial p-i-n nanowires on p-Si for ensemble photodetector application were presented. Various growth methods were explored to mitigate several growth challenges and improve the electrical and optical properties of the nanowires. The optimized GaAsSb axial p-i-n nanowires showed enhanced responsivity, detectivity, and reduced noise level, making them suitable for high-speed optoelectronic applications.
Article
Optics
Xingchen Pan, Jiaxun Song, Hao Hong, Mingrui Luo, Richard Notzel
Summary: A red nanowire LED with an InGaN bulk active region grown on a p-Si (111) substrate is presented. The LED exhibits stable wavelength and narrower linewidth without quantum confined Stark effect as the injection current increases. However, efficiency droop is observed at high injection current. The LED achieves an output power of 0.55 mW and external quantum efficiency of 1.4% at 20 mA (20 A/cm2) with a peak wavelength of 640 nm, reaching 2.3% at 70 mA with a peak wavelength of 625 nm. The use of p-Si substrate allows for large carrier injection currents due to a naturally formed tunnel junction at the n-GaN/p-Si interface, making it ideal for device integration.
Article
Engineering, Electrical & Electronic
Yuangang Wang, Hehe Gong, Yuanjie Lv, Xingchang Fu, Shaobo Dun, Tingting Han, Hongyu Liu, Xingye Zhou, Shixiong Liang, Jiandong Ye, Rong Zhang, Aimin Bu, Shujun Cai, Zhihong Feng
Summary: By implementing a composite terminal structure with a p-NiO junction termination extension and a small-angle beveled field plate, high-performance p-NiO/ss-Ga2O3 heterojunction diodes were successfully demonstrated. This structure significantly increases the breakdown voltage of ss-Ga2O3 and achieves low ON-resistance, making it a promising candidate for various applications.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Chemistry, Multidisciplinary
Kalaivanan Loganathan, Alberto D. Scaccabarozzi, Hendrik Faber, Federico Ferrari, Zhanibek Bizak, Emre Yengel, Dipti R. Naphade, Murali Gedda, Qiao He, Olga Solomeshch, Begimai Adilbekova, Emre Yarali, Leonidas Tsetseris, Khaled N. Salama, Martin Heeney, Nir Tessler, Thomas D. Anthopoulos
Summary: The low carrier mobility of organic semiconductors and the high parasitic resistance and capacitance often encountered in conventional organic Schottky diodes hinder their deployment in emerging radio frequency (RF) electronics. However, this study demonstrates RF Schottky diodes capable of operating in the 5G frequency spectrum by combining self-aligned asymmetric nanogap electrodes with a high mobility organic semiconductor.
ADVANCED MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Julia Valderas-Gutierrez, Rubina Davtyan, Sudhakar Sivakumar, Nicklas Anttu, Yuyu Li, Patrick Flatt, Jae Yen Shin, Christelle N. Prinz, Fredrik Hook, Thoas Fioretos, Martin H. Magnusson, Heiner Linke
Summary: Sensitive detection of low-abundance biomolecules is crucial for diagnostic applications. This study compares the optical sensing performance of semiconductor nanowires produced by aerotaxy and epitaxy techniques. It demonstrates that aerotaxy nanowires show comparable signal enhancement and can achieve single-molecule detection, offering a potential pathway for scalable and low-cost production of highly sensitive nanowire-based platforms for optical biosensing applications. The platforms based on both types of nanowires exhibit higher signal intensity compared to planar glass surfaces, with epitaxy platforms performing slightly better due to higher nanowire density.
ACS APPLIED NANO MATERIALS
(2022)
Article
Computer Science, Hardware & Architecture
Inderpreet Singh
Summary: Incorporating nanomaterials in device structure is crucial to enhance the performance of polymer light emitting diodes (PLEDs), however, challenges such as the non-availability of stable low work function metals for cathode, presence of charge trapping centers in polymer chains, and total internal reflection of light at interfaces hinder the competence of PLEDs. These issues impact electron injection, luminosity, and charge balance in the device, affecting the formation and decay of excitons in the emissive layer.
Article
Chemistry, Physical
Abdurrahman Ali El Yumin, Nicolas F. Zorn, Felix J. Berger, Daniel Heimfarth, Jana Zaumseil
Summary: In this study, we demonstrated exciton and charged exciton electroluminescence from frozen p-n junctions in polymer-sorted carbon nanotube networks. By controlling the initial parameters and lateral bias, we found that the emission intensity and the ratio of charged exciton to exciton were predominantly determined by the tilted potential profile and the number of excess carriers.
Article
Engineering, Electrical & Electronic
Keijo Jacobs, Mietek Bakowski, Per Ranstad, Hans-Peter Nee
Summary: This article investigates the performance of three differently optimized 10-kV SiC p-i-n diodes in high-power converters and compares them. The results show that using SiC diodes can reduce rectifier losses by 37%, compared to the use of Si diodes. The proportion of switching losses to total losses is low, indicating a higher possible operation frequency for SiC diodes.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Materials Science, Multidisciplinary
Nikita Gagrani, Kaushal Vora, Sonachand Adhikari, Yuxin Jiang, Chennupati Jagadish, Hark Hoe Tan
Summary: This study investigates the electrical and optical properties of n-type tin oxide film and explores its application in InP nanowire light emitting diodes. The research finds that the device with lower resistance and higher absorption performs better in terms of output power.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
A. Pilotto, P. Dollfus, J. Saint-Martin, M. Pala
Summary: In this study, the Shockley-Read-Hall (SRH) generation/recombination was incorporated into Non-equilibrium Green's function (NEGF) calculations using a multiphonon relaxation model. The effects of defects on the current-voltage characteristics of GaAs p-i-n diodes and InGaAs tunnel diodes were investigated. The results demonstrate that SRH generation/recombination is responsible for approaching the theoretical ideality factors in the forward bias regime and the recombination current density shows slow variation with applied voltage in the reverse bias regime. Defects located in the center of the active region were found to be the most effective in allowing trap-assisted tunneling. Additionally, the inclusion of SRH recombination in NEGF simulations of Esaki tunnel diodes accurately predicts the realistic degradation of the peak-to-valley current ratio.
SOLID-STATE ELECTRONICS
(2022)
Article
Nanoscience & Nanotechnology
Shasvat Rathod, Monika Snowdon, Joshua Jones, Kaiping Zhang, Peng Peng
Summary: In this study, a fiber laser direct writing (FLDW) process is developed for the simultaneous fabrication of diodes and bipolar junction transistors (BJTs) on flexible polyimide substrates. The fabricated diodes and BJTs demonstrate excellent performance under various operating conditions.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Engineering, Electrical & Electronic
Wenshen Li, Kazuki Nomoto, Zongyang Hu, Debdeep Jena, Huili Grace Xing
Summary: This study provides a comprehensive analysis of the ON-resistance (R-ON) of Ga2O3 trench-MOS Schottky barrier diodes, focusing on the impact of sidewall interface trapping. It was found that increasing forward bias leads to the accumulation of negative charges and slow detrapping near the MOS interface, causing current collapse and delayed turn-on behavior in trench SBDs. Interestingly, the dynamic R-ON under forward-bias stress is lower than the fresh R-ON, which can be attributed to modulation of fin-channel conductivity under forward bias.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Polymer Science
Doan Vu, Wen Liang Tan, Lu He, Alexander Ehm, Dietrich R. T. Zahn, Christopher R. McNeill
Summary: We report the discovery of a third crystalline polymorph of the electron-transporting conjugated polymer P(NDI2OD-T2), called form III, which exhibits an end-on texture. This new polymorph is characterized by the incorporation of two monomer units along the backbone-stacking direction, resulting in a doubling of the unit cell c axis. The formation of form III crystallites is achieved by melt annealing a thin film followed by slow cooling. Analysis using grazing-incidence wide-angle X-ray scattering (GIWAXS) and peak simulation confirms the unique packing of this polymorph. This discovery presents an exciting opportunity to study the structure/function relationships of this important semiconducting polymer.
Article
Chemistry, Physical
Shan He, Yaoyao Han, Jingwei Guo, Kaifeng Wu
Summary: The study explores how entropy can be used to control the emission lifetime in semiconductor nanocrystal-molecular triplet acceptor complexes. Experimental results show that the delayed emission lifetime increases with the ratio of acceptor to nanocrystal, indicating a potential for using entropy to design light-emitting materials with predetermined excited-state lifetimes.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Chie Hou Leong, Mu Wen Chuan, Kien Liong Wong, Faraz Najam, Yun Seop Yu, Michael Loong Peng Tan
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2020)
Article
Engineering, Electrical & Electronic
Faraz Najam, Sangwan Kim, Woo Young Choi, Yun Seop Yu
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2020)
Article
Chemistry, Multidisciplinary
Tae Jun Ahn, Yun Seop Yu
Summary: In this paper, the electrical coupling between the top and bottom transistors in a monolithic 3D inverter (M3INV) stacked with JLFET was investigated. It was found that there is strong coupling in M3INV when T-ILD <= 30 nm. The noise margin of M3INV-MOS is larger and better for inverter characteristics than that of M3INV-JL.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Ngoc Thanh Duong, Chulho Park, Duc Hieu Nguyen, Phuong Huyen Nguyen, Thi Uyen Tran, Dae Young Park, Juchan Lee, Duc Anh Nguyen, Jong Hyeok Oh, Yun Seop Yu, Mun Seok Jeong
Summary: The developed MoTe2 homojunction-based TFET shows promising performance with significantly low sub-thermal swing, high on/off current ratio, strong air stability, and lower supply voltage compared to Silicon technology. This study represents a strategy for van der Waals heterostructure assembly and demonstrates significant progress in TFET research.
Article
Chemistry, Analytical
Jong Hyeok Oh, Yun Seop Yu
Summary: This study introduces an improved macro-model for an N-type feedback field-effect transistor (NFBFET) and verifies its effectiveness through comparison with a previous model and circuit simulation. The new model consists of two parts, a charge integrator circuit and a current generator circuit, addressing previous issues in accurately implementing certain characteristics.
Article
Nanoscience & Nanotechnology
Jihoon Kim, A. Venkatesan, Nhat Anh Nguyen Phan, Yewon Kim, Hanul Kim, Dongmok Whang, Gil-Ho Kim
Summary: The study developed an SBD system using n-type tungsten disulfide (WS2) and demonstrated improved diode characteristics by depositing In and Au on n-type WS2. The SBD showed characteristics close to an ideal diode with improved electrical properties compared to conventional p-n diodes.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Tae Jun Ahn, Sung Kyu Lim, Yun Seop Yu
Summary: The study simulated a monolithic three-dimensional inverter structure and found that interface trap charges generated thermally during integration process can lead to performance degradation, such as increased propagation delay and reduced frequency in logic circuits involving the inverter.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Analytical
Geun Jae Lee, Yun Seop Yu
Summary: The effect of work-function variation on a monolithic 3D inverter structure with stacked MOSFET gates is investigated in this paper. Using TCAD and Monte-Carlo sampling simulation, the impact of the top- and bottom-tier gates' work-function variation on the inverter is studied. It is found that as the interlayer dielectric thickness decreases, the means and standard deviations of electrical parameters rapidly increase, emphasizing the importance of considering coupling and its distribution in M3D circuit simulation.
Article
Chemistry, Analytical
Jong Hyeok Oh, Yun Seop Yu
Summary: A monolithic three-dimensional integrated static random access memory with a feedback field effect transistor (M3D-FBFET-SRAM) was proposed. The electrical characteristics and operation of the FBFET were investigated, along with the electrical coupling between the top and bottom tier transistors. Non-turn-off characteristics were achieved by optimizing the doping profile, and two methods for compensating current level were suggested.
Article
Chemistry, Analytical
Jong Hyeok Oh, Yun Seop Yu
Summary: This study investigated the tunneling effect in a N-type feedback field-effect transistor (NFBFET). The NFBFET has a highly doped N-P junction in the channel region, and when a drain-source voltage is applied, band-to-band tunneling (BTBT) current can be formed on the surface region of the N-P junction. The alignment between the conduction band of the N-region and the valence band of the P-region occurs, resulting in an increase in off-currents. However, as a gate-source voltage is applied, the tunneling rate decreases due to a reduction in the aligned region between bands caused by a stronger gate-field. The tunneling currents eventually vanish before reaching the threshold voltage at the BTBT vanishing point. Increasing the doping concentration in the gated-channel region results in the generation of tunneling current not only on the surface region but also in the bulk region, leading to shorter tunneling lengths and increased leakage currents. The BTBT vanishing point also increases as the tunneling rates at the surface and bulk regions increase.
Article
Chemistry, Multidisciplinary
Seung Su Jeong, Nam Ho Kim, Yun Seop Yu
Summary: In an aging society, the issue of falls among the elderly has become increasingly prominent. This study presents a fall detection system that combines a simple threshold method and long-term memory. The results show that the proposed system achieves higher accuracy compared to previous systems. To address the issue of overfitting, parameter optimization is conducted.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Multidisciplinary
Tae Jun Ahn, Bum Ho Choi, Jae-Woong Yu, Yun Seop Yu
Summary: This study investigates the dependence of the color tunability in DC-voltage-driven organic light-emitting diodes (OLEDs) on the thickness of the metal-free Phthalocyanine (H2Pc) layer. The H2Pc layer, serving as a blue/red emission layer, is deposited on an Alq(3) green emission layer. By varying the thickness of the H2Pc layer from 5 to 30 nm, the researchers analyze the current-voltage-luminance characteristics and color coordinates of the OLEDs.
APPLIED SCIENCES-BASEL
(2023)
Editorial Material
Chemistry, Multidisciplinary
Yun Seop Yu, Kwang-Baek Kim, Dongsik Jo, Hee-Cheol Kim, Jeongwook Seo
APPLIED SCIENCES-BASEL
(2023)
Article
Chemistry, Analytical
Jong Hyeok Oh, Yun Seop Yu
Summary: This study investigates the electrical characteristics and electrical coupling effect of a monolithic 3-dimensional nonvolatile memory. The results show that the memory window and retention time are affected by the thickness of the interlayer dielectric (TILD), and it is necessary to consider the electrical coupling effect when designing circuits with thin TILD.
Article
Chemistry, Physical
Seongsoo Lee, Janghyuk Moon, His Muhammad Bintang, Sunghee Shin, Hun-Gi Jung, Seung-Ho Yu, Si Hyoung Oh, Dongmok Whang, Hee-Dae Lim
Summary: This article introduces a fast ionic conductor based on succinonitrile material, demonstrating its potential application in multivalent-ion batteries. The monolithic succinonitrile material has high conductivity and chemical thermal stability, allowing for simple phase transitions between liquid and solid states. Through density functional theory calculations, the authors explain the origin of its high conductivity.
JOURNAL OF MATERIALS CHEMISTRY A
(2021)
