Article
Chemistry, Physical
Yupiao Wu, Shuo-En Wu, Jinjin Hei, Longhui Zeng, Pei Lin, Zhifeng Shi, Qingming Chen, Xinjian Li, Xuechao Yu, Di Wu
Summary: This study presents the controllable growth of large-area 2D MoSe2 layers and the fabrication of a high-quality n-MoSe2/p-Si van der Waals heterojunction device. The device exhibited a self-driven broadband photoresponse with impressive responsivity, specific detectivity, and response time. Furthermore, a 4 x 4 integrated heterojunction device array was achieved with good uniformity and satisfying imaging capability. The large-area 2D MoSe2 layer and its heterojunction device array hold great promise for high-performance photodetection and imaging applications in integrated optoelectronic systems.
Article
Nanoscience & Nanotechnology
Juanmei Duan, Phanish Chava, Mahdi Ghorbani-Asl, YangFan Lu, Denise Erb, Liang Hu, Ahmad Echresh, Lars Rebohle, Artur Erbe, Arkady Krasheninnikov, Manfred Helm, Yu-Jia Zeng, Shengqiang Zhou, Slawomir Prucnal
Summary: This study presents a high-performance and self-powered photodetector based on a MoSe2/FePS3 type-II n-p heterojunction. The photodetector operates at room temperature under zero bias and ambient conditions, exhibiting a wide working range and superior responsivity and quantum efficiency.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Xiaoli Ma, Shaohua Fu, Jianwei Ding, Meng Liu, Ang Bian, Fang Hong, Jiatao Sun, Xiaoxian Zhang, Xiaohui Yu, Dawei He
Summary: Researchers have successfully achieved quantitative tuning of intralayer excitons in WS2/ MoSe2 heterostructures and observed the transition from intralayer excitons to interlayer excitons. The energy of interlayer excitons is in a locked or superstable state, unaffected by pressure.
Article
Chemistry, Physical
Ningning Jiang, You Xie, Sufang Wang, Yuling Song, Liyong Chen, Wei Han, Xinwen Jin, Zixuan Zhou, Zhengxin Yan
Summary: A novel BC6N/BN van der Waals heterostructure is fabricated. The structural stability, electronic structure, and carrier mobility of the BC6N/BN heterostructure induced by in-plane uniaxial and biaxial strains are systematically investigated. The results suggest that the electronic structure and carrier mobility of the BC6N/BN heterostructure can be modulated by in-plane strains, indicating its potential for designing next-generation nanoelectronics devices.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Juanmei Duan, Phanish Chava, Mahdi Ghorbani-Asl, Denise Erb, Liang Hu, Arkady Krasheninnikov, Harald Schneider, Lars Rebohle, Artur Erbe, Manfred Helm, Yu-Jia Zeng, Shengqiang Zhou, Slawomir Prucnal
Summary: This study successfully enhanced the emission and stability of trions by constructing a MoSe2/FePS3 van der Waals heterostructure, and found that a good effect was achieved through type-I band alignment.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Pengyu Li, Yinghe Zhao, Huiqiao Li, Tianyou Zhai
Summary: This study systematically investigates the working mechanisms of Sb2O3 and two Sb2O3-like molecules (As2O3 and Bi2O3) as dielectrics, using a combination of first-principles calculations and gate leakage current theories. It is found that molecules-based vdW dielectrics have a significant advantage over conventional materials, as defects have hardly any impact on their insulating properties. Furthermore, the study reveals that Sb2O3 faces challenges in meeting the requirements for both p-MOS and n-MOS devices, while As2O3 can serve as a dielectric for both types. This research provides a theoretical foundation for the application of molecules-based vdW dielectrics and offers a competitive choice (As2O3) for optimizing the dielectric layer in 2D vdW semiconductor-based CMOS devices, with profound implications for the future semiconductor industry.
Article
Nanoscience & Nanotechnology
Subhajit Jana, Sourabh Pal, Shivakiran B. N. Bhaktha, Samit K. Ray
Summary: This study reports the enhanced photodetection properties of MoSe2/Au-ZnO vertical heterostructures by investigating the synergistic effect of Au nanoislands on the optical response of ZnO nanorods and MoSe2 nanoflakes. The plasmonic effects mediated strong light-matter interactions in the Au-ZnO hybrids, leading to energy transfer and enhanced signal throughout the operational bandwidth of the devices. The use of 2D/1D mixed-dimensional heterostructures and resonant coupling with strategically integrated plasmonic nanoislands make these devices highly responsive broadband photodetectors for future nanophotonic applications.
ACS APPLIED NANO MATERIALS
(2022)
Article
Physics, Condensed Matter
Xu Zhao, Meng Pei, Congxin Xia, Tianxing Wang, Xianqi Dai, Shuyi Wei
Summary: Based on first-principles calculations, this study investigates the structural stability, electronic, and optical properties of PtSe2, Janus XPtY, and h-BN monolayers, as well as their van der Waals heterostructures (vdWHs) with BN monolayer. The findings reveal a broad optical absorption range and different types of band alignment for PtSe2 (XPtY)/BN vdWHs, suggesting their promising applications in photodetectors and nanoelectronic devices.
MICRO AND NANOSTRUCTURES
(2022)
Article
Engineering, Electrical & Electronic
Longhui Zeng, Wei Han, Shuo-En Wu, Di Wu, Shu Ping Lau, Yuen Hong Tsang
Summary: Platinum diselenide has emerged as an attractive material for highly sensitive infrared photodetection due to its unique properties. We successfully assembled a high-performance photodetector using PtSe2/pyramid Si mixed-dimensional van der Waals Schottky junction, and achieved an appealing device performance for room-temperature broadband IR photodetection.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Materials Science, Multidisciplinary
Chunyu Li, Zhiming Wu, Chaoyi Zhang, Silu Peng, Jiayue Han, Meiyu He, Xiang Dong, Jun Gou, Jun Wang, Yadong Jiang
Summary: A high-performance self-powered photodetector based on an all-2D van der Waals heterojunction of metallic 2H-NbSe2 and semiconducting MoSe2 is fabricated, exhibiting high rectification ratio, responsivity, and fast response/recovery time. This study demonstrates the potential of 2D metallic NbSe2 as an electrode for realizing a high-performance broadband photodetector for near-infrared communication.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Physics, Applied
Shih-Po Chien, Bor-Wei Liang, Wen-Hao Chang, Bo-Wen Wang, Yi-Jie Feng, Yi-Cheng Chen, Yann-Wen Lan
Summary: We present the fabrication and characterization of a flash memory device based on a van der Waals heterostructure comprising graphene, hexagonal boron nitride, and molybdenum disulfide. The device exhibits versatile functionalities and demonstrates memtransistor-like behavior, making it a promising candidate for synaptic devices and neuromorphic computing. The heterostructure allows for the manipulation of charge concentration in the floating gate through control gate voltage, resulting in conductance switching. Moreover, the overlap structure of the floating gate and source-drain electrodes enables memtransistor-like operations, where the writing processes rely on the source-drain voltage. By varying carrier storage concentrations in the graphene floating gate, multiple memory states can be achieved, offering analog information processing capabilities.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Taewook Kim, Donghee Kang, Sol Lee, Yeonsu Jeong, Hyunmin Cho, Junho Kim, Heesun Bae, Yeonjin Yi, Kwanpyo Kim, Seongil Im
Summary: This study focuses on MoSe2/MoSe2 homo-stack transistors and their nonvolatile memory behavior, which can be controlled by modifying the stack interfaces.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Bi Luo, Peng Wu, Jiafeng Zhang, Liang Cao, Chunhui Wang, Bin Lu, Bao Zhang, Xing Ou
Summary: A two-dimensional space confined strategy is proposed to construct van der Waals heterostructures for superior potassium-ion battery (PIB) anodes. The synergistic effects in the 2D heterostructure greatly enhance electron transportation and ions diffusion, while inhibiting polysulfide dissolution for increased structural durability. As a result, the synthesized C/MoS2/G anode demonstrates remarkable K-storage performance with high reversible capacity, excellent rate capability, and superior long-cycling stability.
Article
Chemistry, Multidisciplinary
Kohei Sakanashi, Peter Kruger, Kenji Watanabe, Takashi Taniguchi, Gil-Ho Kim, David K. Ferry, Jonathan P. Bird, Nobuyuki Aoki
Summary: In this study, a quantum point contact structure was achieved in a p-type trilayer tungsten diselenide-based van der Waals heterostructure using a modified van der Waals contact method. Clear quantized conductance and pinch-off states were observed through dual-gating control, indicating the presence of intrinsic spin-polarized quantum point contact features. Conductance plateaus and quarter plateaus were observed at specific bias voltage conditions.
Article
Chemistry, Multidisciplinary
Christian Baeuml, Lorenz Bauriedl, Magdalena Marganska, Milena Grifoni, Christoph Strunk, Nicola Paradiso
Summary: In this study, long-range superconducting correlations were observed in a several-micrometers-long carbon nanotube bundle encapsulated in a van der Waals stack between hBN and NbSe2. The behavior of supercurrent in the nanotube demonstrated characteristics similar to that of the parent Ising superconductor.
Article
Chemistry, Multidisciplinary
Jae-Sil Song, Yong Seob Park, Nam-Hoon Kim
Summary: The study investigated the use of DLC thin films prepared by a PECVD system as an ARC for DSSCs, analyzing the impact of film thickness on physical and optical properties. It was found that the 60 nm thick PECVD DLC ARC showed excellent performance for DSSCs, with significantly improved conversion efficiency.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Sergey P. Zimin, Ildar I. Amirov, Sergey V. Vasilev, Ivan S. Fedorov, Leonid A. Mazaletskiy, Nam-Hoon Kim
Summary: After plasma treatment of Cu2-xSe films at average ion energies of 25 and 200 eV, changes in surface morphology and chemical composition were observed, with the composition changing from x = 0.25 to x = 0.10 to x = 0.00.
APPLIED SCIENCES-BASEL
(2021)
Article
Engineering, Electrical & Electronic
Abdelkader Abderrahmane, Changlim Woo, Pil Ju Ko
Summary: The study reports the electrical and optoelectronic performance of 2D MoSe2 and its heterojunction with BP, showing improved characteristics for the BP/MoSe2 heterojunction which can be utilized as a self-powered photodetector.
JOURNAL OF ELECTRONIC MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Ilyes Baba-Ahmed, Daniel Gherca, Alexandra-Raluca Iordan, Mircea Nicolae Palamaru, Carmen Mita, Rachid Baghdad, Gabriel Ababei, Nicoleta Lupu, Mohamed Amine Benamar, Abdelkader Abderrahmane, Tiberiu Roman, Georgiana Bulai, Liviu Leontie, Adrian Iulian Borhan
Summary: In this research, a highly porous foam SrTiO3/NiFe2O4 heterostructure was formed using joint solid-state and sol-gel auto-combustion techniques. The self-assembly of SrTiO3 due to the gelation process of the nickel ferrite was proposed as the mechanism for the highly porous framework formation. Various spectrophotometric techniques were used to investigate the structural, morphological, optical, magnetic, and dielectric properties of the synthesized samples. The 75STO/25NFO heterostructure exhibited higher specific magnetization, coercivity, and permittivity values.
Article
Crystallography
Sergey P. Zimin, Nikolai N. Kolesnikov, Ildar I. Amirov, Viktor V. Naumov, Egor S. Gorlachev, Sara Kim, Nam-Hoon Kim
Summary: (Summary in English:)
The nanostructuring of (100) PbS single crystal surface under argon plasma treatment conditions was studied. It was found that different ion energy and sputtering time parameters influenced the formation and morphology of nanostructures. By adjusting the treatment conditions, various nanostructures including nanotips, submicron cones, cruciform nanostructures, and submicron quasi-spherical lead structures could be formed. The nanostructuring mechanisms involved a surface micromasking mechanism and a vapor-liquid-solid mechanism.
Article
Computer Science, Information Systems
Sara Kim, Nam-Hoon Kim
Summary: This study discovered colossal values of the Seebeck coefficient in Mg-poor Mg2Sn films in the temperature range 600-700 K. The films were prepared using the RF magnetron co-sputtering method and showed a structural phase transition from orthorhombic to cubic. The calculated energy band structure and density-of-state matched the experimental data.
Article
Materials Science, Multidisciplinary
Sakal Pech, Sara Kim, Nam-Hoon Kim
Summary: This study investigates the crystalline quality of polycrystalline beta-Ga2O3 films through rapid thermal annealing. The results show that by annealing at 900°C under a N2 gas atmosphere for 45 minutes, optimized polycrystalline beta-Ga2O3 films with improved crystal structure can be obtained.
Article
Materials Science, Multidisciplinary
Abdelkader Abderrahmane, Changlim Woo, Pil-Ju Ko
Summary: In this study, a novel heterojunction field-effect transistor (HJFET) using two-dimensional graphene, molybdenum diselenide, and black phosphorus was fabricated with the protection of hexagonal boron nitride to prevent device degradation. The electrical and optoelectronic characteristics of the graphene/n-MoSe2 and graphene/n-MoSe2/p-BP heterojunctions were measured. The n-MoSe2/p-BP heterojunction exhibited a potential barrier at the interface, allowing the use of BP as a top-gate contact to adjust the electrical and optoelectronic performances of the graphene/n-MoSe2 heterojunctions. The graphene/n-MoSe2 junction field-effect transistor with p-BP as gate contact demonstrated the best optoelectronic performance, making it extremely promising for photodetection applications.
Article
Materials Science, Ceramics
Jihye Kang, Jaeyong Yun, Yoo-Young Oh, Sung-Jin Kim, Masao Kamiko, Nam-Hoon Kim, Jung-Hyuk Koh
Summary: This study explores stress engineering in multilayered structures of Al-doped ZnO thin films by controlling defects in them. It is found that defects and dislocations in thin films can deteriorate their electrical and optical properties. Layered Al-doped ZnO thin films with different thicknesses were prepared to investigate the interface effects and electron motion in them.
JOURNAL OF THE KOREAN CERAMIC SOCIETY
(2022)
Article
Crystallography
Abdelkader Abderrahmane, Pan-Gum Jung, Changlim Woo, Pil Ju Ko
Summary: In this study, metal-insulator-semiconductor field-effect transistors (MISFETs) based on nanolayered molybdenum diselenide (MoSe2) were fabricated using silicon dioxide (SiO2) and silicon nitride (SiN) as insulator materials. Morphological and electrical characterizations showed that the devices exhibited good electronic performance with high mobility and high I-on/I-off ratios exceeding 10(4). However, the subthreshold swing was somewhat high due to the dimensions of the devices.
Article
Chemistry, Physical
Seok-Mo Kang, Tae Wan Kim, Nam-Hoon Kim, Sung-Jin Kim, Jung-Hyuk Koh
Summary: The composition of lead-free piezoelectric ceramics (1 - x)(Bi0.5Na0.5)TiO3-x(Ba0.5Sr0.5)TiO3 with excellent piezoelectric properties was investigated in this study. Crystal analysis, electrical and piezoelectric properties were analyzed based on the content of BST composition. It was found that the optimal composition was 0.12 BST, which exhibited a phase change from rhombohedral to tetragonal structure, the highest permittivity, and the highest values of P-r, d(33), k(p), and Curie temperature (T-m). These results confirm that 0.12 BST is the optimal composition for (1 - x)BNT-xBST piezoelectric ceramics.
Article
Chemistry, Multidisciplinary
Laid Kadri, Abdelkader Abderrahmane, Georgiana Bulai, Aurelian Carlescu, Corneliu Doroftei, Iuliana Motrescu, Silviu Gurlui, Liviu Leontie, Mohamed Adnane
Summary: TiO2-SiO2 nanocomposite thin films were fabricated and characterized, and their amorphous structure and homogeneous distribution were observed. The deposition temperature had an effect on the optical properties, with lower temperature resulting in increased light transmission in the visible and ultraviolet ranges.
Article
Chemistry, Multidisciplinary
Sakal Pech, Yun Ju Rou, Sara Kim, Kang-Yeon Lee, Nam-Hoon Kim
Summary: The improvement in crystallinity of non-selenized CIGS thin films was achieved by compensating for stoichiometric deviations through the co-sputtering of Te and rapid thermal annealing. The prepared CIGS:Te thin films exhibited better crystallinity with large grain size, clear grain boundaries, and low microstrain and dislocation density. These films also showed improved optical properties compared to conventional CIGS thin films, making them suitable for low-cost commercialization without the selenization process.
APPLIED SCIENCES-BASEL
(2023)
Article
Crystallography
Abdelkader Abderrahmane, Khaled Senouci, Belkacem Hachemi, Pil Ju Ko
Summary: In recent years, there has been significant interest in unidimensional photonic crystal-based biosensors for label-free bio-detection. These biosensors utilize materials with different refractive indices and a cavity region for biomolecule injection. This study numerically investigated the optical properties of different unidimensional photonic crystals and focused on the detection of four types of extracellular vesicles. The [PbTiO3/MgF2] photonic crystal biosensor showed the best biosensing performance, with a sensitivity of 511.3 nm/RIU. Overall, this study provides valuable insights into using perovskite materials, particularly LiTaO3 and PbTiO3, for photonic crystal-based biosensors in various applications.
Article
Chemistry, Physical
Sara Kim, Yong-Seok Lee, Nam-Hoon Kim
Summary: P-type Cu-Se thin films were successfully deposited on glass substrates at room temperature using radio frequency magnetron sputtering with a multi-component CuSe2 target. The sputtering power was found to have a significant impact on the homogeneity and stoichiometry of the thin films. Optimized sputtering power resulted in more homogenous thin films with improved stoichiometry, despite exhibiting Se deficiency at all depths.
