作者：
Huamei Zuo;Shixiang Zhan;Wangping Xu;Xiaolin Wei;Juexian Cao
期刊：
Sensors and Actuators B-Chemical,2024年409:135604 ISSN：0925-4005
通讯作者：
Wangping Xu<&wdkj&>Juexian Cao
作者机构：
Department of Physics & Hunan Institute of Advanced Sensing and Information Technology, Xiangtan University, Xiangtan 411105, PR China;College of Physics and Electronics Engineering, Hengyang Normal University, Hengyang 421002, PR China;[Huamei Zuo; Shixiang Zhan; Wangping Xu; Juexian Cao] Department of Physics & Hunan Institute of Advanced Sensing and Information Technology, Xiangtan University,Xiangtan 411105,PR China;[Xiaolin Wei] Department of Physics & Hunan Institute of Advanced Sensing and Information Technology, Xiangtan University,Xiangtan 411105,PR China<&wdkj&>College of Physics and Electronics Engineering, Hengyang Normal University,Hengyang 421002,PR China
通讯机构：
[Wangping Xu; Juexian Cao] D;Department of Physics & Hunan Institute of Advanced Sensing and Information Technology, Xiangtan University, Xiangtan 411105, PR China
摘要：
Screening sensitive materials is one of the keys to designing high-performance carbon nanotube-based field-effect transistor gas sensors. Here, we proposed a reliable way (e.g., H2S) to design sensitive materials with high efficiency based on theory and experiment. Our results demonstrated that the interaction between H2S and the sensitive materials must satisfy both energy level and parity match, and the maximum overlap of the orbital wave function. Especially, the gas ΔQ exhibits a strong linear scaling with the metal φ (ΔQ∝φ). Meanwhile, Δφ will result in changes in the threshold voltage of the sensor (ΔVth∝Δφ) in experiments, which would lead to different response intensities. Therefore, the greater the ΔQ, the more changes in the threshold voltage, and corresponding higher response intensity. Expectedly, our experimental results show that the response intensity at equivalent concentrations is in high agreement with the theory (Pt > Pd > Ag), and the limit of H2S detection is low to 20 ppb.
作者机构：
[Ting Lv; Meng Ge; Yang Zeng; Degao Xu; Gang Ouyang] Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Key Laboratory for Matter Microstructure and Function of Hunan Province, School of Physics and Electronics, Hunan Normal University , Changsha 410081, China;[Yipeng Zhao] College of Physics and Electronic Engineering, Hengyang Normal University , Hengyang 421008, China
通讯机构：
[Gang Ouyang] K;Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Key Laboratory for Matter Microstructure and Function of Hunan Province, School of Physics and Electronics, Hunan Normal University , Changsha 410081, China
摘要：
Designing direct Z-scheme heterostructure is an effective strategy to enhance redox ability, greatly raising the attention of photocatalysis in recent years. Here, we design 24 diverse vertical MS2/Si2PAs (M = Zr, Hf) heterostructures with different stacking configurations. Four kinds of heterostructures with different interlayer contacts are taken as examples to investigate the geometry, stability, and electronic properties, as well as the photocatalytic mechanism based on the first-principles calculations. We find that the competitiveness of MS2/Si2PAs (M = Zr, Hf) heterostructures is attributed to their excellent visible light absorption (∼2 × 105 cm−1), ultrafast carrier migration (∼13 587.28 cm2 V−1 s−1), and high solar-to-hydrogen efficiency (10.02%), indicating that this kind of system can be as a promising candidate in the field of semiconductor photocatalysis.
摘要：
Organic deep-red fluorescent materials have a wide range of applications in organic light-emitting diodes (OLEDs), biological imaging, night-vision equipment, and other fields. Here, we designed and synthesized a new deep-red emissive donor-acceptor (D -A) compound TPANZPPICN, whose non-doped OLED achieves stable pure deep-red electroluminescence (EL) at 692 nm with a maximum external quantum efficiency (EQE) of 2.67 % in non-doped OLED and a maximum EQE of 7.96 % at 660 nm in doped OLED. Magneto-electroluminescence (MEL) measurements reveal a negative response in the doped OLED, which is a significant character of reversed intersystem crossing (RISC) on high-lying excited states. Both theoretical calculations and experimental results confirm that the hot-exciton mechanism is responsible for the high efficiency EL of doped OLED, which proves to be a novel approach to realize the efficient deep-red organic fluorescent OLEDs.
摘要：
Graphene is always used to construct two-dimensional (2D) van der Waals (vdW) heterostructures due to its excellent performance. Hydrogenated phosphorus carbides (HPC or PCH), as novel 2D carbon-based materials, are predicted to be potential for nanoelectronics and optoelectronics. Herein, we explore the electronic prop-erties of vdW heterostructure of graphene and hydrogenated phosphorus carbides under both strain and electric field by using first-principles calculations. The results demonstrate that the Schottky barrier height (SBH) and band gap of the heterostructures can be effectively modulated by in-plane uniaxial or biaxial strain, but the Schottky contact type (n-type or p-type) could not be modified by the strain alone in the investigated range (from-10% to 10%). Interestingly, when the strain and electric field are simultaneously applied to the heterostructure, not only the SBH and band gap but also the Schottky contact type could be modulated effectively. The results open a new avenue for design of 2D carbon-based nanoelectronic and optoelectronic devices.
作者机构：
[Wang, Qianqian; Feng, Zhuoer; Ang, Lay Kee; Tho, Che Chen; Su, Tong; Yang, Shengyuan A.; Wu, Qingyun; Ang, Yee Sin] Singapore Univ Technol & Design, Sci Math & Technol Cluster, Singapore 487372, Singapore.;[Wang, Guangzhao; Tang, Qin; Yu, Chenjiang] Yangtze Normal Univ, Sch Elect Informat Engn, Key Lab Extraordinary Bond Engn & Adv Mat Technol, Chongqing 408100, Peoples R China.;[Nguyen, C. V.] Le Quy Don Tech Univ, Dept Mat Sci & Engn, Hanoi 100000, Vietnam.;[Ong, Wee-Liat] Zhejiang Univ, ZJU UIUC Inst, Coll Energy Engn, Haining 314400, Zhejiang, Peoples R China.;[Ong, Wee-Liat] Zhejiang Univ, State Key Lab Clean Energy Utilizat, Hangzhou 310027, Zhejiang, Peoples R China.
通讯机构：
[Guangzhao Wang; Yee Sin Ang; Guangzhao Wang Guangzhao Wang Guangzhao Wang; Yee Sin Ang Yee Sin Ang Yee Sin Ang] S;Science Mathematics and Technology Cluster, Singapore University of Technology and Design, Singapore, 487372 Singapore<&wdkj&>School of Electronic Information Engineering, Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing, Yangtze Normal University, Chongqing, 408100 China
关键词：
2D materials;density functional theory simulations;electrical contacts;excitonic solar cells;van der Waals heterostructures
摘要：
Although the d-band center theory can well describe the interaction between gas molecules and transition metal surfaces, the detailed reaction process and specific adsorption conditions are unclear. Hence, in this work, we systematically studied the adsorption mechanism, adsorption conditions, and recovery time of NO and NO2 molecules on different transition metals (Cu, Ag, Au, Ni, Pd, Pt, Rh, Ru, Tc, Mo, Nb, and Zr) surfaces by first-principles. The results indicated that the charge transfers from the dz2, dxz, and dyz orbitals of substrate atoms to the HOMOs/LUMOs of NO and NO2. Moreover, we demonstrate that the interaction orbitals between the NO/NO2 and the metal atoms excellently correspond with the match of energy level and parity, and the maximum overlap of the orbital wave function. Interestingly, the excellent linear scaling between charge transfer and the d-band center, work function, and matrix element (V-ad(2)) of metals has been confirmed. Specifically, the different recovery times of these systems at different temperatures were explored. Our results can provide a feasible way for exploring gas-sensitive materials in the experiments.
摘要：
High-performance photodetectors hold promising potential in optical communication and imaging systems. However, conventional counterparts are suffering narrow detection range, high power consumption, and poor polarization sensitivity. Characteristics originating from switchable polarization in ferroelectrics can be used to optimize the photo-to-electric procedure and improve the photodetection performance. In this regard, we constructed a configuration by integrating 2-dimensional molybdenum disulfide (MoS(2)) with ferroelectric lithium niobate (LiNbO(3)), resulting in the MoS(2)/LiNbO(3) heterostructured photodetector. Benefiting from the pyroelectric effect of LiNbO(3), the limitation of bandgap on the detection range can be broken, thus broadening the response band of the detector to 365 to 1,064 nm, as well as enabling the self-powered characteristic. Meanwhile, high carrier mobility and decent light absorbance of MoS(2) introduce robust light-matter interactions with the underlying LiNbO(3), leading to ultrafast rise/fall times of ≈150 μs/250 μs and switching ratios of up to ≈190. Moreover, the highest responsivity, specific detectivity, and external quantum efficiency achieved were 17.3 A·W(-1), 4.3 × 10(11) Jones, and 4,645.78%, respectively. Furthermore, because of the anisotropy of the spontaneous-polarized LiNbO(3) substrate, the photocurrent of the device achieved a dichroic ratio of 7.42, comparing favorably to most MoS(2)-based photodetectors. This work demonstrates the integration potential between ferroelectric LiNbO(3) and 2-dimensional materials for high-performance photodetection.
通讯机构：
[Xiaohui Ling] L;Laboratory for Spin-Orbit Photonics, College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang 421002, People's Republic of China
关键词：
angular momentum;photonic orbital Hall effect;vortex phase;mode decomposition
摘要：
The photonic orbital Hall effect (POHE) refers to the vortex-dependent beam shifts, which is generally believed to result from the conversion of intrinsic orbital angular momentum (IOAM) to extrinsic orbital angular momentum (EOAM). However, the physical mechanism of the POHE, such as how the IOAM is converted to the EOAM, remains further elucidation. In this paper, we re-examine the POHE of a vortex beam with additional IOAM illuminating at an optically thin slab by means of vortex mode decomposition. By considering the competition and coupling between the radial and azimuthal vortex harmonics of the abnormal mode in the transmitted beam, it is found that the underlying mechanism of the POHE is in fact a spin-to-orbital angular momentum (OAM) conversion process. And the IOAM carried by the incident beam is directly superimposed on the OAM obtained during the conversion. Our findings not only offer an alternative perspective for understanding the POHE, but also exhibit application potential in orbit-orbit and spin-orbit optical components.
作者机构：
[Huang, F. F.; Sun, L. Z.] Xiangtan Univ, Sch Mat Sci & Engn, Hunan Prov Key Lab Thin Film Mat & Devices, Xiangtan 411105, Peoples R China.;[Ma, Z. S.; He, S. D.; Zhou, P.; Li, W. Q.] Xiangtan Univ, Sch Mat Sci & Engn, Xiangtan 411105, Peoples R China.;[Tan, R.] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.
摘要：
Second-order topological phases in artificial systems have been extensively studied, but studies in the phonons of atomic materials are limited. In this paper, we propose that phononic second-order topological phase exists in C3N , a previously synthesized and intensively investigated two-dimensional material. Its nontrivial phase arises from the mismatch between the Wannier centers of the out-of-plane phonon modes and the atomic positions. Using a simplified force constant model, we find that gapped edge modes and in-gap corner modes only exist on the structures with broken pure-carbon-ring terminations, and this unexpected phenomenon can be explained by the electronlike filling anomaly for phonons. Further calculations reveal that these corner modes are robust to external disturbances. The nontrivial phononic phase in C3N provides an avenue in crystalline materials to explore higher-order topological phases in Bose systems.
作者机构：
[Yuxue Mo; Yuxue Mo Yuxue Mo Yuxue Mo] College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang, 421002 P. R. China;[Xuan Zhou; Fang Yu; Liling Liao; Xinru Yong; Fangming Zhang; Dongyang Li; Qian Zhou; Haiqing Zhou; Xuan Zhou Xuan Zhou Xuan Zhou; Fang Yu Fang Yu Fang Yu; Liling Liao Liling Liao Liling Liao; Xinru Yong Xinru Yong Xinru Yong; Fangming Zhang Fangming Zhang Fangming Zhang; Dongyang Li Dongyang Li Dongyang Li; Qian Zhou Qian Zhou Qian Zhou; Haiqing Zhou Haiqing Zhou Haiqing Zhou] Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Key Laboratory for Matter Microstructure and Function of Hunan Province, Department of Physics and Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha, 410081 P. R. China;[Tian Sheng; Tian Sheng Tian Sheng Tian Sheng] College of Chemistry and Materials Science, Anhui Normal University, Wuhu, 241000 P. R. China
通讯机构：
[Fang Yu; Haiqing Zhou; Fang Yu Fang Yu Fang Yu; Haiqing Zhou Haiqing Zhou Haiqing Zhou] K;[Tian Sheng; Tian Sheng Tian Sheng Tian Sheng] C;Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Key Laboratory for Matter Microstructure and Function of Hunan Province, Department of Physics and Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha, 410081 P. R. China<&wdkj&>College of Chemistry and Materials Science, Anhui Normal University, Wuhu, 241000 P. R. China
关键词：
bifunctional water splitting;cobalt nitride;heterostructures;iron phosphide;large current density
摘要：
Self‐supported Fe2P/Co2N porous heterostructure arrays are in situ constructed with abundant iron sites exposing at the surface, which presents superb bifunctional catalytic activity for hydrogen and oxygen evolution reactions in base, substantially expediting the overall water splitting at 500 mA cm−2 with only 1.663 V, prominently superior to IrO2(+)//Pt(−) coupled electrodes and most of non‐noble bifunctional electrocatalysts. Abstract Alkaline water electrolysis is a commercially viable technology for green H2 production using renewable electricity from intermittent solar or wind energy, but very few non‐noble bifunctional catalysts simultaneously exhibit superb catalytic efficiency and stability at large current densities for hydrogen and oxygen evolution reactions (HER and OER, respectively), especially for iron‐based catalysts. Given that iron is the most abundant and least expensive transition metal, iron‐based compounds are very attractive low‐cost targets as active electrocatalysts for bifunctional water splitting with large‐current durability. Herein, the in situ construction of a self‐supported Fe2P/Co2N porous heterostructure arrays possessing superb bifunctional catalytic activity in base is reported, featured by low overpotentials of 131 and 283 mV to attain a current density of 500 mA cm−2 for HER and OER, respectively, outperforming most of non‐noble bifunctional electrocatalysts reported hitherto. Particularly, this hybrid catalyst also displays an excellent overall water splitting activity, requiring low voltages of 1.561 and 1.663 V to attain 100 and 500 mA cm−2 with excellent durability in 1 m KOH, respectively. Most importantly, the catalyst is stable for >120 h, even when the current density is 500 mA cm−2, which is prominently superior to IrO2(+)//Pt(−) coupled noble electrodes, and is among the very best bifunctional catalysts reported thus far. Detailed theoretical calculations reveal that the interfacial interaction between Fe2P and Co2N can further improve the H* binding energy at the iron sites.
通讯机构：
[Yanliang Tan] C;College of Physics and Electronic Engineering , Hengyang Normal University, Hengyang, Hunan Province 421008, China
摘要：
Radon-222 (Rn-222) exhalation rate is vital for estimating radiation risk from many kinds of materials. AlphaGUARD measures the radon concentration based on the ionization chamber principle, which is currently recognized as a reference instrument to measure radon. In China, measurements of radon exhalation rate are performed by AlphaGUARD operated in flow-through mode on a reference device to verify measurement accuracy. These measurements are performed in both open and closed loop. AlphaGUARD can fast rapidly the variation of the radon concentration in the chamber, which is tightly pressed against the surface of the medium to accumulate the exhaled radon. When the model is used to obtain the radon exhalation rate, the radon exhalation rates obtained by nonlinear data fitting on the measured radon concentrations are similar to the reference value of the device. The difference of radon exhalation rate values of six measurements is small.
作者机构：
[Tan, Yanliang; Mo, Yuxue; Deng, Yanhong; Tang, Yuxiang; Zhou, Wanying] Hengyang Normal Univ, Coll Phys & Elect Engn, Henghua Rd 16, Hengyang City 421002, Hunan Province, Peoples R China.;[Lin, Jin-Xia] Xiamen Univ, State Key Lab Phys Chem Solid Surface, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China.;[Sheng, Tian] Anhui Normal Univ, Coll Chem & Mat Sci, Wuhu 241000, Peoples R China.
通讯机构：
[Mo, YX ] H;Hengyang Normal Univ, Coll Phys & Elect Engn, Henghua Rd 16, Hengyang City 421002, Hunan Province, Peoples R China.
关键词：
Lithium-sulfur batteries;Strong adsorption effect;First principal calculation;High sulfur loading
摘要：
The lithium-sulfur (Li-S) batteries have achieved important developments, but still suffer from some main intrinsic disadvantages, such as the dissolution and diffusion of the lithium polysulfides (LiPSs). In response, here we develop a Mo2C/MoO3 heterostructure as the interlayer to restrain the leakage and migration of LiPSs. Owing to its good conductivity and excellent electronic transport, this heterostructure can perform excellently as an ideal carrier for providing reduction reaction sites of LiPSs conversion, thus greatly improving the electrochemical properties of Mo2C/MoO3 for Li-S batteries. The resultant Mo2C/MoO3 electrodes can deliver a high specific capacity of 1346 mAh g- 1 at 0.1C and long-term cycling stability (660 mAh g- 1 after 800 cycles at 2C) with a low capacity decay rate of 0.05% per cycle, indicating high sulfur utilization and fast kinetic conversion of LiPSs and Li2S. When the sulfur loading is increased to 4.34 mg cm-2, the initial discharge capacity and areal capacity of the Mo2C/MoO3 electrode at 0.1C is still up to 1405 mAh g- 1 and 6.1 mAh cm-2 with a coulombic efficiency of 99% in the first cycle, indicating faster LiPSs conversion. First-principle calculations reveal that the as-synthesized LiPSs species are selectively adsorbed on the MoO3 (001) and Mo2C (001) surface. This work provides an alternative strategy toward high-performance Li-S battery with high sulfur loading.
期刊：
Results in Physics,2023年54:107047 ISSN：2211-3797
通讯作者：
Lan, Y;Huang, WQ
作者机构：
[Zhang, Jing; Luo, Jia-Cheng; He, Zi-Cheng] Hengyang Normal Univ, Nanyue Coll, Dept Phys & Elect Informat Sci, Hengyang 421008, Peoples R China.;[Lan, Yu] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Huang, Wei-Qing; Huang, Gui-Fang] Hunan Univ, Sch Phys & Elect, Dept Appl Phys, Changsha 410082, Peoples R China.;[Hu, Wangyu] Hunan Univ, Sch Mat Sci & Engn, Changsha 410082, Peoples R China.
通讯机构：
[Lan, Y ; Huang, WQ ] H;Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;Hunan Univ, Sch Phys & Elect, Dept Appl Phys, Changsha 410082, Peoples R China.
关键词：
Schottky barrier;Metal-semiconductor contact;van der Waals heterostructure;Electric field;First -principles calculations
摘要：
Two-dimensional (2D) transition metal carbides, nitrides, or carbonitrides (MXenes) have emerged as promising ultrathin materials for nanoelectronics and optoelectronics. However, the contact barrier at metal --semiconductor (MS) junctions still significantly limits the device's performance. Here, we propose a novel strategy-functionalizing accompanied with external electric fields-to tune the MS contact nature in MXene-based van der Waals (vdW) heterostructures, taking 2D Ti2C as an example, by means of first-principles calcu-lations. Different Ti2CO2/Ti2CX2 (X = OH or S) vdW heterostructures are designed via functionalizing Ti2C metals to contact with 2D Ti2CO2. We reveal that OH functionalized vdW MS heterostructure (Ti2CO2/Ti2C (OH)2) can be tuned to the Ohmic contact owing to the strong interlayer interaction inducing a large number of interlayer transferred electrons; while for the sulfurized vdW MS heterostructure (Ti2CO2/Ti2CS2), its Schottky barrier height and contact type can be effectively tuned by external electric field due to the rather weak inter -layer interaction. Our work paves a new way for the construction of 2D MXene-based vdW MS heterostructures and demonstrates the great potential of 2D MXenes in future nanoelectronics and optoelectronics.
作者机构：
[Zhou, Zhong-Peng; Deng, Xiao-Hui; Zhang, Qian-Kui; Tang, Zhen-Kun] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Zhou, Zhong-Peng; Tong, Chuan-Jia; Hao, Ning-Jing] Cent South Univ, Sch Phys & Elect, Hunan Key Lab Nanophoton & Devices, Hunan Key Lab Super Microstructure & Ultrafast Pro, Changsha 410083, Peoples R China.;[Zhang, Hui] Shenyang Univ, Normal Sch, Shenyang 110044, Peoples R China.
通讯机构：
[Zhen-Kun Tang] C;[Chuan-Jia Tong] H;Hunan Key Laboratory of Nanophotonics and Devices, Hunan Key Laboratory of Super-Microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha 410083, China<&wdkj&>College of Physics and Electronics Engineering, Hengyang Normal University, Hengyang 421002, China
通讯机构：
[Tang, ZK ] H;Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.
摘要：
Two-dimensional Ruddlesden-Popper (2D RP) perovskites can form layered protective materials using long organic cations as "barrier" caps, which is expected to solve the problem of instability of perovskites in the working environment. In this work, we systematically studied the 2D Ruddlesden-Popper (C(6)H(5)CH(2)NH(3))(2)PbI(4) hybrid perovskites using density functional theory. The results reveal that the 2D (C(6)H(5)CH(2)NH(3))(2)PbI(4) perovskites are semiconductors with band gaps of 2.22 eV. The optical absorption peak of the 2D (C(6)H(5)CH(2)NH(3))(2)PbI(4) perovskite structure is located at 532 nm in the visible region. Interestingly, the optical absorption spectrum of the 2D (C(6)H(5)CH(2)NH(3))(2)PbI(4) perovskite structure enhanced under suitable strains. The highest optical absorption peak appears in 2D (C(6)H(5)CH(2)NH(3))(2)PbI(4) under a -2% strain, and its theoretical photoelectric conversion efficiency is 28.5%. More interestingly, the replacement of surface I atoms with Br is another ways to enhance the optical absorption spectrum of the 2D (C(6)H(5)CH(2)NH(3))(2)PbI(4) perovskite structure. The optical absorption peak blue-shifts to the high energy region, which has higher solar energy flux density than the low energy region. The good stability, tuneable band gap and excellent theoretical photoelectric conversion efficiency of the 2D (C(6)H(5)CH(2)NH(3))(2)PbI(4) perovskite structure make it a promising candidate for novel 2D hybrid perovskite based photoelectronic devices and solar cells.
