Article
Chemistry, Multidisciplinary
Md Tarik Hossain, Tadasha Jena, Upasana Nath, Manabendra Sarma, P. K. Giri
Summary: The success of non-van der Waals two-dimensional bismuth oxyselenide crystals in optoelectronics has opened up opportunities to explore their fundamental properties. However, the origin of photoluminescence and the effect of growth substrates on the structure and optical properties of these crystals remain unclear. This study reveals that the formation of multiple excitons in momentum valleys is responsible for broadband absorption and visible photoluminescence in few-layer thick bismuth oxyselenide. It also demonstrates that different growth substrates introduce strain and doping, thereby modulating the morphology, absorption, and photoluminescence properties.
Article
Chemistry, Physical
Vinod K. Sangwan, Joohoon Kang, David Lam, J. Tyler Gish, Spencer A. Wells, Jan Luxa, James P. Male, G. Jeffrey Snyder, Zdenek Sofer, Mark C. Hersam
Summary: Bi2O2Se APDs exhibit high sensitivity and bandwidth, characterized by a unique reverse biased Schottky diode model, suitable for a diverse range of high-performance photodetector applications.
Article
Physics, Applied
Md Tarik Hossain, P. K. Giri
Summary: In this study, air-stable ultrathin Bi2O2Se semiconductor was successfully grown by chemical vapor deposition (CVD), showing high structural and chemical uniformity. The phonon dispersion and in-plane thermal conductivity of LBOS were investigated through Raman studies and estimation techniques, providing insights into the electron-phonon and phonon-phonon interactions in non-van der Waals 2D materials.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Physics, Applied
Hui Zeng, Jun Zhao, Da-Zhi Ding
Summary: By using density-functional theory calculations, researchers investigated the hydrogenation effects on two-dimensional (2D) orthorhombic diboron diphosphorus (O-B2P2). The results show that hydrogenation can transform the pristine O-B2P2 into a wide and indirect-bandgap semiconductor with bandgap values depending on the hydrogenation configurations. The hydrogenated O-B2P2 nanostructures exhibit strong anisotropic mechanical and carrier transport properties, making them potential candidates for high-performance electronic devices and sensors.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Qifeng Cai, Congwei Tan, Jingyue Wang, Teng Tu, Shuang Sun, Xiaokang Li, Baotong Zhang, Haixia Li, Xiaoyan Xu, Xia An, Xing Zhang, Ru Huang, Hailin Peng, Ming He, Ming Li
Summary: This research characterizes the electronic transport features of two-dimensional Bi-2 O-2 Se semiconductor nanosheets, achieving high-efficiency field-effect transport and heterojunction transport across vertical interlayers.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Ce-Wen Hu, Yi Yang, Chunju Hou, Tong-Xiang Liang
Summary: In this study, the electronic structures of 2D Bi2O2Se were systematically investigated, revealing a weak quantum size effect in multi-layers and a large tunability of band gaps in monolayer and bilayer through strain modulation. The sensitivity of band edge with strain was attributed to the increase in Bi-Se bond length with lattice stretch, reducing the strength of the bond and lowering the energies of band edge states due to their antibonding nature. Highly tunable electronic properties via changing thickness or adding strain provide Bi2O2Se with more possibilities for electronic and optoelectronic device applications.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Nanoscience & Nanotechnology
Xiaopin Lai, Kaiqing Liang, Yang Su, Kunbin Guo, Xin Wang, Yanpei Wan, Cuiqiong Ye, Chengke Zhou, Rongjia Chen, Wenhua Gao, Yuping Chen, Wen Lin, Wenxiu Ni, Yan Lin, Kwan-Ming Ng
Summary: In this study, a PbS/Au-layered substrate was designed to efficiently characterize the lipidomic profiles of lung cancer (LC) patient serum for early diagnosis. The optimized substrate promotes the generation of excited electrons and creates an enhanced electric field, facilitating ion adduction formation and enhancing detection sensitivity. Through multivariate statistics and machine learning, a distinct lipidomic biomarker panel is successfully identified for early diagnosis and staging of LC. This innovative substrate shows potential as a sensitive platform for accurate diagnosis of LC and development of lipidomic-based diagnostic tools for other cancers.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
P. Marauhn, M. Rohlfing
Summary: The electronic and optical properties of layered materials are affected by the image charge effect, which is caused by the dielectric environment. This effect varies between layers in multilayer structures, but its implications on interlayer coupling are not well understood. A macroscopic dielectric continuum model is proposed to describe the variation of dielectric screening effects, and an efficient method for incorporating this effect in electronic structure calculations is presented. By applying this method to multilayer MoS2, an energetic decoupling of the surface layer is observed, leading to the formation of a surface-layer band gap. Furthermore, the image charge effect can cause spatial modulation of interlayer coupling by changing the band alignment between layers.
Review
Energy & Fuels
Omar Sarwar Chaudhary, Mouloud Denai, Shady S. Refaat, Georgios Pissanidis
Summary: This paper discusses the growing demand for power devices with higher capabilities in blocking voltage, switching frequencies, temperature withstand, power density, efficiency, and reliability, which cannot be met by traditional Si-based semiconductor devices. It introduces wide bandgap (WBG) power semiconductor materials such as SiC, GaN, and Dia, which possess superior material properties and are expected to gradually replace the Si-based devices in various power electronics applications. The paper highlights the technical and market potential of WBG semiconductors and analyzes their cost, energy impact, size, and efficiency improvement in different applications.
Article
Materials Science, Multidisciplinary
Sheelbhadra Chatterjee, Munshi Sahid Hossain, Sariful Molla, Subhajit Bandyopadhyay
Summary: Researchers have achieved reversible aggregation-disaggregation behavior of a tetraphenylethene (TPE)-based molecule through photochemical reactions. The change in the molecule's morphology due to the reactions significantly affects its conductance.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Nanoscience & Nanotechnology
Rui Zhu, Zhibin Gao, Qijie Liang, Junxiong Hu, Jian-Sheng Wang, Cheng-Wei Qiu, Andrew Thye Shen Wee
Summary: Anisotropic magnetoresistance has been studied and demonstrated in layered non-magnetic semiconducting PdSe2 flakes, showing differences in magnetoresistance along different crystalline axes. The magnetoresistance can be flexibly tuned by applying a gate voltage, supported by ab initio density functional calculations. These findings advance the understanding of magnetoresistance in anisotropic transition-metal dichalcogenides and pave the way for potential applications in anisotropic spintronic devices.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Engineering, Electrical & Electronic
Jun Cao, Tianshu Li, Hongze Gao, Xin Cong, Miao-Ling Lin, Nicholas Russo, Weijun Luo, Siyuan Ding, Zifan Wang, Kevin E. Smith, Ping-Heng Tan, Qiong Ma, Xi Ling
Summary: This study demonstrates the synthesis of few-nanometer-thick GaN crystals via in situ atomic substitution of layered GaS flakes. The obtained ultrathin GaN flakes show high crystallinity and tunable thicknesses, with a blue-shifted band edge photoluminescence compared to bulk GaN. This breakthrough provides a promising method for future investigations into fundamental physics and potential device applications.
JOURNAL OF ELECTRONIC MATERIALS
(2023)
Article
Chemistry, Physical
Fangqi Liu, Qiang Yu, Junfei Xue, Bowang Shu, Cangdong Zheng, Haiqin Deng, Xiaolin Zhang, Pengwei Gong, Mingyan Chen, Hai Lin, Sicong Zhu, Jian Wang, Jian Wu
Summary: Black arsenic phosphorus is an important material for future photonic devices. The band gap of the material switches from direct to indirect when the x value is 0.75. The absorption characteristics of the material also vary with different x values, which is significant for the application of photodetectors.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Fangqi Liu, Qiang Yu, Junfei Xue, Bowang Shu, Cangdong Zheng, Haiqin Deng, Xiaolin Zhang, Pengwei Gong, Mingyan Chen, Hai Lin, Sicong Zhu, Jian Wang, Jian Wu
Summary: Black arsenic phosphorus material demonstrates different optical and electronic properties at different x values, with the indirect band gap characteristics at x = 0.75 being particularly noteworthy.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Huili Shan, Qinming He, Xin Luo, Yue Zheng
Summary: In this work, the potential applications of h-BN nanosheets and nanoribbons as wide band gap semiconductors are explored in terms of carrier mobility. Through first-principles calculations and deformation potential theory, the phonon-limited carrier mobility of monolayer h-BN and nanoribbons is predicted at room temperature. The study finds that armchair-edge h-BN nanoribbons in the Nac = 3p + 1 family exhibit larger hole mobility, with the highest value reaching 1.9 x 104 cm2 V-1 s-1 in narrow nanoribbons. The delocalization of occupied orbitals of valence electrons in the transport direction contributes to the high hole mobility.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Xueting Dai, Feng Qin, Caiyu Qiu, Ling Zhou, Junwei Huang, Fanghua Cheng, Xiangyu Bi, Caorong Zhang, Zeya Li, Ming Tang, Shengqiang Wu, Xiaoxu Zhao, Yangfan Lu, Huiyang Gou, Hongtao Yuan
Summary: The interaction between light and matter in low-dimensional quantum-confined structures can greatly influence the optical properties of materials and have applications in optoelectronics. In the anisotropic layered silicon diphosphide (SiP2) crystal, the quasi-one-dimensional (1D) phosphorus-phosphorus (P-P) chains create an unconventional quasi-1D excitonic state and a unique 1D quantum-confined system. By alloying SiP2 with a similar element, researchers can study the properties of these excitons and phonons associated with the quasi-1D P-P chains, as well as their strong interaction. However, the experimental observation and understanding of SiP2 with isoelectronic dopants is still unclear. In this study, the authors use photoluminescence and Raman spectroscopy measurements to observe the redshift of the confined excitonic peak and the stiffening of the phonon vibration mode in Si(P1-xAsx)2 alloys with increasing arsenic (As) compositions. This anomalous stiffening is attributed to the selective substitution of As atoms for P atoms within the P-P chains, as confirmed by scanning transmission electron microscopy. These optical spectrum changes provide insights into 1D quantum confinement in semiconductors and offer opportunities for photonic device applications.
Article
Chemistry, Multidisciplinary
De Zhang, Xincan Wang, Hong Wu, Yuling Huang, Sikang Zheng, Bin Zhang, Huixia Fu, Zien Cheng, Pengfei Jiang, Guang Han, Guoyu Wang, Xiaoyuan Zhou, Xu Lu
Summary: High electrical performance in Cu3SbS4 is achieved by creating high valence vacancies and using aluminum as a vacancy stabilizer. The addition of CuAlS2 improves the average power factor to 16.1 mu W cm(-1) K-2, and further addition of AgAlS2 reduces the thermal conductivity, resulting in a peak zT of 1.3 and an average zT of 0.77. These findings provide insights into a new strategy for high-efficiency doping in thermoelectric materials.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Multidisciplinary Sciences
Dexi Shao, Junze Deng, Haohao Sheng, Ruihan Zhang, Hongming Weng, Zhong Fang, Xing-Qiu Chen, Yan Sun, Zhijun Wang
Summary: In this study, a (2x2) patterned PtTe2 monolayer with a kagome lattice structure formed by Te vacancies was investigated. The monolayer was found to exhibit large and tunable spin Hall conductivity (SHC) and excellent hydrogen evolution reaction (HER) activity. The large SHC was attributed to the Rashba spin-orbit coupling induced by the Te vacancies, and the nontrivial Z(2) invariant was determined by the presence of a direct band gap. The calculated SHC ranged from 1.25x10(3h/e) (omega)(-1) to -1.2 x 10(3) to 3.1x10(3h/e) (omega)(-1) by adjusting the chemical potential. Additionally, the monolayer also showed promising HER activity. This work not only provides a new strategy to search for 2D materials with large SHC, but also demonstrates a feasible system with tunable SHC and excellent HER activity.
Article
Chemistry, Multidisciplinary
Xiangyu Bi, Feifan Tian, Ganyu Chen, Zeya Li, Feng Qin, Yang-Yang Lv, Junwei Huang, Caiyu Qiu, Lingyi Ao, Yanbin Chen, Genda Gu, Yanfeng Chen, Hongtao Yuan
Summary: Superconducting quantum interferometer device (SQUID) plays a crucial role in understanding electromagnetic properties and emergent phenomena in quantum materials. By using a specially designed superconducting nano-hole array, it is demonstrated that the contactless detection of magnetic properties and quantized vortices in micro-sized superconducting nanoflakes can be achieved. This new approach provides a quantitative evaluation of the density of pinning centers of the quantized vortices on such micro-sized superconducting samples, which is not accessible with conventional SQUID detection.
ADVANCED MATERIALS
(2023)
Article
Astronomy & Astrophysics
Xiaofeng Mai, Bo Zhang, M. J. Reid, L. Moscadelli, Shuangjing Xu, Yan Sun, Jingdong Zhang, Wen Chen, Shiming Wen, Qiuyi Luo, Karl M. Menten, Xingwu Zheng, Andreas Brunthaler, Ye Xu, Guangli Wang
Summary: We present the measurement of the trigonometric parallax of 22 GHz water masers in the massive star-forming region G034.43+0.24. The obtained parallax corresponds to a distance of 3.03(-0.16)(+0.17) kpc. The motion and distribution of water masers in the region provide valuable insights into the structure and dynamics of the Sagittarius spiral arm.
ASTROPHYSICAL JOURNAL
(2023)
Article
Materials Science, Coatings & Films
Yuanfeng Ding, Bingxin Li, Jinshan Yao, Huanhuan Song, Lian Wei, Yang Lu, Junwei Huang, Hongtao Yuan, Hong Lu, Yan-Feng Chen
Summary: We grew alpha-Sn films on two different substrates with different sample structures using molecular beam epitaxy. The presence of a mixture of alpha and beta phases in the Sn film was confirmed. Multiple superconducting transitions were observed in these alpha-Sn/beta-Sn mixed films, with enhanced critical temperatures, critical fields, and shorter coherence lengths compared to bulk beta-Sn. Angle-dependent measurements demonstrated the two-dimensional nature, and magnetization measurements indicated a type-II superconductor. The multiple superconducting transitions were attributed to the beta-Sn islands formed within the film.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
Article
Chemistry, Multidisciplinary
Xuanyi Li, Xifan Xu, Hui Zhou, Huaxian Jia, En Wang, Huixia Fu, Jia-Tao Sun, Sheng Meng
Summary: The emergence of long-range ferromagnetic quantum anomalous Hall (QAH) insulators has opened up new possibilities for combining topology and magnetism in low dimensions. By using atom-thin Chern insulator monolayer MnBr3, the topologically nontrivial electronic states can be systematically tuned by magnetic orders and external fields in stacked Chern insulator bilayers. The bilayers show high-Chern-number QAH states with quantized Hall plateaus and specific magneto-optical Kerr angles in ferromagnetic cases, and Berry curvature singularity induced by electrostatic fields or lasers in antiferromagnetic cases, leading to a novel layer Hall effect depending on the chirality of irradiated circularly polarized light. These findings suggest a universal routine to modulate d-orbital-dominated topological Dirac fermions.
Article
Chemistry, Physical
Congcong Zhang, Teng Tu, Jingyue Wang, Yongchao Zhu, Congwei Tan, Liang Chen, Mei Wu, Ruixue Zhu, Yizhou Liu, Huixia Fu, Jia Yu, Yichi Zhang, Xuzhong Cong, Xuehan Zhou, Jiaji Zhao, Tianran Li, Zhimin Liao, Xiaosong Wu, Keji Lai, Binghai Yan, Peng Gao, Qianqian Huang, Hai Xu, Huiping Hu, Hongtao Liu, Jianbo Yin, Hailin Peng
Summary: The scaling of silicon-based transistors faces challenges such as interface imperfections and gate current leakage at sub-ten-nanometre technology nodes. To achieve smaller channel sizes, less interfacial scattering, and more efficient gate-field penetration, high-mobility two-dimensional layered semiconductors are expected as channel materials. However, progress in 2D electronics is hindered by the lack of a high dielectric constant dielectric with an atomically flat and dangling-bond-free surface.
Article
Multidisciplinary Sciences
Di Wang, Ruifeng Tang, Huai Lin, Long Liu, Nuo Xu, Yan Sun, Xuefeng Zhao, Ziwei Wang, Dandan Wang, Zhihong Mai, Yongjian Zhou, Nan Gao, Cheng Song, Lijun Zhu, Tom Wu, Ming Liu, Guozhong Xing
Summary: A new type of spiking neuron with leaky-integrate-fire and self-reset (LIFT) characteristics is achieved by manipulating the magnetic domain wall motion in a synthetic antiferromagnetic (SAF) heterostructure. The spintronic LIFT neurons demonstrate high firing rate (up to 17 MHz) and low energy consumption (486 fJ/spike), and a spiking neuron circuit is implemented with fast latency (170 ps) and low power consumption (90.99 mu W). A two-layer spiking neural network based on these spintronic LIFT neurons achieves 88.5% accuracy on the handwritten digit database benchmark.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Yingjian Li, Caiyu Qiu, Huajian Ji, Siyu Duan, Feng Qin, Zeya Li, Peng Chen, Junwei Huang, Geliang Yu, Hongtao Yuan
Summary: By combining microspheres and optical or Raman microscopy, super-resolution imaging beyond the diffraction limit and enhancement of Raman signals can be achieved, providing abundant spectroscopic information on materials. However, microsphere-aided super-resolution scanning photocurrent imaging remains challenging. In this study, a super-resolution photocurrent and spectral microscopy equipped with silica dielectric microspheres is presented, which allows for order of magnitude enhancements in Raman and photoluminescence signals, as well as surpassing the spatial resolutions of the original confocal system.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Wenkai Wang, Zhihua Sun, Jiajia Wu, Dun Zhang, Peng Wang, Ce Li, Liyang Zhu, Yaohua Gao, Yan Sun
Summary: Carbon source starvation can promote steel corrosion through extracellular electron transfer (EET) in the presence of a pure culture. The impact of carbon source starvation on corrosion induced by mixed strains is still unknown. This study investigated the impact of carbon source starvation on EH40 steel corrosion in the presence of Desulfovibrio vulgaris and Pseudomonas aeruginosa, and the results showed that the corrosion behavior depended on the addition of nitrate.
Article
Materials Science, Multidisciplinary
Heyu Zhu, Jiantao Wang, Yun Chen, Mingfeng Liu, Hui Ma, Yan Sun, Peitao Liu, Xing-Qiu Chen
Summary: In this study, the effects of alloying elements on the generalized stacking fault energies (GSFEs) of Ni and Ni3Al were systematically investigated using ab initio density functional theory calculations. It was found that most alloying elements decrease the unstable stacking fault energy and stable stacking fault energy of Ni, except for Mn, Fe, and Co. For Ni3Al, most alloying elements exhibit a strong preference for the Al site and increase the GSFEs. Re, W, Mo, Os, Ru, and Ir were identified as excellent strengthening alloying elements for Ni and Ni3Al. The findings provide valuable insights for the design of next-generation high-performance single-crystal superalloys.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Physics, Multidisciplinary
Ruixiang Zhou, Xuefeng Zhang, Gang Li
Summary: In this study, we have investigated the interplay of Ruderman-Kittel-Kasuya-Yosida (RKKY) and Kondo couplings in the Doniach phase diagram on square and triangular lattices using advanced many-body techniques. Our findings suggest that the simple Doniach phase diagram is inadequate to fully capture the complexity of the competition even on these simple lattices. We discovered that geometric frustration plays a significant role in suppressing long-range antiferromagnetic order on the triangular lattice and that the formation of Kondo singlets occurs within the long-range magnetic phase on the square lattice.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Tianran Yang, Liyu Zhang, Chin -Wei Wang, Fei Gao, Yuanying Xia, Pengfei Jiang, Long Zhang, Xinrun Mi, Mingquan He, Yisheng Chai, Xiaoyuan Zhou, Huixia Fu, Weijun Ren, Aifeng Wang
Summary: Single crystals of LaMn0.86Sb2 were synthesized using the flux method. Band structure calculations confirmed the presence of Dirac dispersion below the Fermi level, as expected for square-net-based materials. Magnetization measurements and neutron diffraction analysis revealed a G-type antiferromagnetic structure with weak spin canting below TN = 146 K. A spin-flop transition was observed with external magnetic fields applied parallel to the c-axis. Negative magnetoresistance at low temperatures suggests a spin alignment effect. LaMn1-xSb2 demonstrates Dirac dispersion and tunable magnetism due to vacancies, making it a potential platform for studying the interplay of magnetism, charge transport, and topological bands.
Article
Materials Science, Multidisciplinary
Ling Zhou, Junwei Huang, Ming Tang, Caiyu Qiu, Feng Qin, Caorong Zhang, Zeya Li, Di Wu, Hongtao Yuan
Summary: Magnetic tunnel junctions (MTJs) are spintronic devices based on the spin valve effect, and can be improved by utilizing advanced 2D ferromagnetic materials or exploring the gate-tunable magnetic properties. Recent research has shown that gate-tunable MTJ devices can be achieved by electrolyte gating, allowing for adjustable magnetoresistance ratio and magnetoresistance switching strength.