Article
Physics, Applied
Zhongwang Wang, Yahua Yuan, Xiaochi Liu, Manoharan Muruganathan, Hiroshi Mizuta, Jian Sun
Summary: In this study, coupled double-quantum dot-like transport was demonstrated in a controllably doped graphene nanoribbon. By utilizing controlled doping and electrically tunable inter-dot coupling, the transition from strongly to weakly coupled double quantum dots was observed.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Multidisciplinary
Fei Gao, Rodrigo E. E. Menchon, Aran Garcia-Lekue, Mads Brandbyge
Summary: Recently, researchers have combined porphyrin units with graphene nanoribbons (Por-GNR) to create various structures. In this study, the authors use first-principles calculations to investigate the properties of two experimentally feasible Por-GNR hybrids. They find that one of the hybrids has a small band gap and can be used as electrodes in devices. By embedding a Fe atom in the porphyrin, a spin-polarized ground state is achieved. The authors examine the spin transport properties of a 2-terminal setup involving a Fe-Por-GNR between Por-GNR electrodes and observe a Fano anti-resonance feature. They also demonstrate how mechanical strain or chemical adsorption can induce spin-crossover, leading to different spin states. These findings provide valuable insights for the development of carbon-based spintronics and chemical sensing applications.
COMMUNICATIONS PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Luis M. Mateo, Qiang Sun, Kristjan Eimre, Carlo A. Pignedoli, Tomas Torres, Roman Fasel, Giovanni Bottari
Summary: On-surface synthesis is a powerful tool for constructing large, planar, pi-conjugated structures that are inaccessible through standard solution chemistry, with graphene nanoribbons (GNRs) holding a prime position in nanoelectronics due to their outstanding properties. Using appropriately designed molecular precursors allows the synthesis of functionalized GNRs, leading to nanostructured hybrids with superior physicochemical properties. Porphyrins (Pors) stand out among potential partners for GNRs due to their rich chemistry, robustness, and electronic richness, but constructing GNR hybrids with such pi-conjugated macrocycles is challenging and examples are scarce.
Article
Materials Science, Multidisciplinary
Mark J. J. Mangnus, Felix R. Fischer, Michael F. Crommie, Ingmar Swart, Peter H. Jacobse
Summary: In this paper, the relationship between the geometry of graphene nanoribbons (GNRs) and their charge transport characteristics is explored through in situ through-transport measurements and the development of a comprehensive transport model. The combined experimental and theoretical efforts help elucidate general charge transport phenomena in GNRs and GNR heterostructures.
Article
Engineering, Electrical & Electronic
Yawei Lv, Yuan Liu, Lei Liao, Wenjing Qin, Changzhong Jiang
Summary: The study shows that nuclear quantization in armchair graphene nanoribbons can enhance atomic vibration and lead to band structure deformation, affecting the energy gap and electronic performance. It is noteworthy that electronic fluctuations can significantly impact device performance.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Chemistry, Physical
Mingxuan Cao, Min Wang, Zhiwen Wang, Luhao Zang, Hao Liu, Shuping Xiao, Matthew M. F. Yuen, Ying Wang, Yating Zhang, Jianquan Yao
Summary: An improvement in random lasers based on quantum dot/graphene-doped polymer was observed, with the factors of multiple light-scattering and graphene surface plasmon resonance attributed to it. The study compared the emission characteristics of quantum dots doped with graphene oxide and reduced graphene oxide, and found that the hybrid of quantum dots and reduced graphene oxide exhibited a lower laser emission threshold. The emission modes and thresholds were strongly influenced by both the graphene doping concentration and the external temperature.
Article
Optics
Sahar Armaghani, Ali Rostami, Peyman Mirtaheri
Summary: This theoretical study investigates the optical properties of a graphene nanoribbon with a quantum dot (QD). The position and radius of the QD strongly influence the dipole-dipole interaction between the graphene nanoribbon and the QD. The study suggests that periodic optical structures can be introduced in the nanoscale by inserting QDs in a periodic array on the graphene nanoribbon, enabling the design of applications such as reflectors, couplers, and wavelength filters.
Article
Physics, Multidisciplinary
Sofia Sanz, Nick Papior, Geza Giedke, Daniel Sanchez-Portal, Mads Brandbyge, Thomas Frederiksen
Summary: This study investigated structures composed of narrow zigzag graphene nanoribbons (GNRs) and found that the beam-splitting effect can survive under Coulomb repulsion and a spin-dependent scattering potential can emerge. The researchers also discovered that this is a general feature with edge-polarized nanoribbons, and near-perfect polarization can be achieved by joining several junctions in series.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Sahar Armaghani, Ali Rostami, Peyman Mirtaheri
Summary: In this study, the effects of an array of quantum dots on a charged graphene plate were theoretically analyzed, and it was successfully transformed into a graphene nanotube. This achievement has significant potential applications in the electro-optical industry.
Article
Chemistry, Multidisciplinary
Yuqi Yang, Baolong Wang, Xu Zhang, Hongchuang Li, Sen Yue, Yifan Zhang, Yunhuang Yang, Maili Liu, Chaohui Ye, Peng Huang, Xin Zhou
Summary: In this study, acidity-activated graphene quantum dots-based nanotransformers (GQD NT) were developed as photosensitizer vehicles for long-period tumor imaging and repeated PDT. The GQD NT actively targeted tumor tissues and underwent loosening and enlargement in tumor acidity, enabling longer tumor retention. The GQD NT also generated mild hyperthermia upon laser irradiation, enhancing cell membrane permeability and promoting photosensitizer uptake. This study overcame the overdose obstacle in repeated PDT by using programmed deformation to enhance accumulation, retention, and release of photosensitizers in tumors.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Haiqing Wan, Xianbo Xiao, Yee Sin Ang
Summary: This study investigates the quantum transport properties of graphene nanoribbons (GNRs) with different edge doping strategies. The results show that boron and nitrogen edge doping on the electrodes region can significantly alter the electronic band structures and transport properties of the system. Remarkably, this edge engineering strategy transforms GNR into a molecular spintronic nanodevice with exceptional transport properties, such as dual spin filtering effect, spin rectifier, and negative differential resistance. These findings suggest a potential route for developing high-performance graphene spintronics technology using an electrode edge engineering strategy.
Article
Physics, Condensed Matter
Xiao-Dong Tan, Le Cui, Ya-Feng Song
Summary: In a zigzag graphene nanoribbon thermalized with a reservoir at temperature T, entanglement dynamics between two edge spins display oscillating behaviors in the presence of an external magnetic field. The oscillations strongly depend on the field frequency and relative location between spins. At critical field frequencies, the entanglement shows a periodic structure. Regular and symmetrical oscillating patterns occur at low temperatures, while irregular distortions appear at high temperatures due to thermal fluctuations. Even at room temperature, entanglement between two edge spins in ZGNR still maintains a nontrivial value.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Quantum Science & Technology
Xiao-Dong Tan, Le Zhang, Xun-Feng Yuan, Shu-Ting Li
Summary: Classical correlations are found to be unaffected by noisy channels and depend only on spin correlation function, while quantum correlations in ZGNR show robustness against thermal fluctuations, with sudden entanglement and dissonance behaviors observed. Understanding the dynamics of classical and quantum correlations can provide insights into spin dynamics in graphene nanoribbons.
QUANTUM INFORMATION PROCESSING
(2022)
Article
Chemistry, Physical
Lijun Liang, Xin Shen, Mengdi Zhou, Yijian Chen, Xudong Lu, Li Zhang, Wei Wang, Jia-Wei Shen
Summary: In this study, molecular dynamics simulation was used to investigate the adsorption behavior and structural changes of single-stranded and double-stranded DNA on the surfaces of graphene quantum dots with different sizes and oxidation levels. The results showed that single-stranded DNA can strongly adsorb and lay flat on the surface, while double-stranded DNA prefers to orient vertically.
Article
Nanoscience & Nanotechnology
Xiao-Dong Tan, Ya-Feng Song, Li -Jun Li, Le Zhang
Summary: In this study, the teleportation of Werner state using electronic spin states at the ends of two same narrow armchair graphene nanoribbons as quantum channels in an amplitude-damping environment is investigated. The effects of amplitude damping, temperature T, and Coulomb repulsion U on the dynamics of channel state, output state, and the fidelity between output and input states are discussed in detail. The average fidelity of teleportation is also calculated to characterize the quality of the teleported state. The results show that the narrow armchair graphene nanoribbon is a promising solid-state system for quantum teleportation, reaching an average fidelity of more than 80% under the amplitude-damping channel when T < 40 K and U < 6eV.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2023)
Article
Physics, Condensed Matter
A. Jbeli, N. Zeiri, N. Yahyaoui, P. Baser, M. Said
Summary: The electronic and optical properties of CdSe/ZnSe semiconductor core/shell quantum dots with hydrogenic donor impurity were investigated theoretically. The perturbation and variational methods were used to calculate the binding energy, photoionization cross-section, polarizability, and diamagnetic susceptibility of the excited impurity under various conditions. A significant stark shift in the binding energy was observed under the influence of an external electric field.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Rahat Batool, Tariq Mahmood, Sajid Mahmood, Abdul Aziz Bhatti
Summary: This study investigates the effects of alkali metal doping (Na, K, Cs) on MAPbI3 through compositional engineering. The results show that doping Na, K, and Cs can improve the phase stability, thermodynamic stability, and optical absorption of MAPbI3.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
N. A. N. M. Nor, M. A. H. Razali, W. H. A. W. K. Annuar, N. N. Alam, F. N. Sazman, N. H. M. Zaki, A. S. Kamisan, A. I. Kamisan, M. H. Samat, A. M. M. Ali, O. H. Hassan, B. U. Haq, M. Z. A. Yahya, M. F. M. Taib
Summary: This study investigates the potential of quaternary chalcogenides semiconductors as thin film solar cell absorbers using density functional theory (DFT) and density functional theory plus Hubbard U (DFT + U) approach. The results show that by applying Hubbard U terms, the electronic band gaps can be accurately predicted, providing valuable insights for finding cost-effective new thin film solar cell materials.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Ashwani Kumar, Anuj Kumar, Mohaseen S. Tamboli, Mohd Ubaidullah, J. Jayarubi, S. K. Tripathi
Summary: In this study, lead-based perovskite solar cells are replaced by bismuth-based perovskite cells to overcome their instability and toxicity. CsBi3I10 perovskite films are fabricated using a modified drop-casting process, and the effects of post-annealing temperature on the morphological, structural, and optical properties are investigated. The photovoltaic performance of the cells without a hole transport layer is also quantitatively evaluated.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Yang Gao, Shu-Ming Chen, Shuo Cao, Shang-Zhou Zhang, Philippe Djemia, Qing-Miao Hu
Summary: This study investigates the phase stability, elastic modulus, and hardness of ternary nitride Ti1-xAlxN. It is found that the hardness increases with the Al content x. The cubic B1 structure is more stable for x < about 0.75, while the hexagonal structure (B4) is more stable for x > about 0.75. The composition dependent hardness and phase decomposition contribute to the convex shaped hardness curve of Ti1-xAlxN.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Fengqi Wang, Qinyan Ye, Xulin He, Kun Luo, Xiaolong Ran, Xingping Zheng, Cheng Liao, Ru Li
Summary: This report uses rigorous calculations based on density functional theory to study the piezoelectric and elastic properties of wurtzite aluminum nitride (w-AlN) with single- and co-alloying by Hf (or Zr) and Sc. The research finds that the (HfSc)0.375Al0.625N and (ZrSc)0.375Al0.625N with stable wurtzite phase have a large piezoelectric coefficient d33 of 49.18 pC/N and 47.00 pC/N, respectively. However, the piezoelectric voltage constant g33 and electromechanical coupling constant k233 of HfAlN, ZrAlN, HfScAlN, and ZrScAlN are smaller than that of ScAlN, which is attributed to the large dielectric constant epsilon 33 of Hf (or Zr) alloying samples. Furthermore, the calculations of internal parameter u and bond angle alpha elucidate the brittle-to-ductile transformation in alloying w-AlN crystal structure. Electronic structure calculations show that the bandgap decreases almost linearly with the increase of alloying concentration, and the Hf (or Zr) alloying compounds become n-type semiconductors due to the existing high-charge states.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
S. R. Athul, K. Arun, S. Swathi, U. D. Remya, Andrea Dzubinska, Marian Reiffers, Nagalakshmi Ramamoorthi
Summary: The magnetic and magnetocaloric characteristics of Ho6FeSb2 have been studied. The compound exhibits two second-order ferromagnetic transitions, enabling hysteresis-free magnetocaloric effect across a wide temperature range. The alloy has high relative cooling power and magnetoresistance, making it suitable for hysteresis-free magnetocaloric applications.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Reena Sharma, Neelam Hooda, Ashima Hooda, Satish Khasa
Summary: A polycrystalline double perovskite La2CoMnO6 sample was prepared and its structural, dielectric and magnetic properties were investigated. The sample exhibited complex structures and magnetic behavior, and showed good conductivity and dielectric performance. Its multi-domain magnetic structure suggests its suitability for memory device applications.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Shubha Dubey, Jisha A. Abraham, Kumud Dubey, Vineet Sahu, Anchit Modi, G. Pagare, N. K. Gaur
Summary: This study investigates the optoelectronic, thermodynamic, thermoelectric, and mechanical stability properties of RhTiP Half Heusler semiconductors. The results show that RhTiP is a non-magnetic material with confirmed mechanical stability. It is found to be an indirect-bandgap semiconductor with a good Seebeck coefficient. This study suggests that RhTiP has promising applications in the thermoelectric and optoelectronic fields.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Xun Xie, Jiong-Ju Hao, Hong-Wei Yang
Summary: This work presents a multilayer film structure that uses optical resonance to prepare highly efficient and saturated red, green, and blue transmittance colors. Numerical simulations and analysis show that the structure can produce R, G, and B colors with a purity comparable to standard RGB colors, while maintaining efficient transmission efficiency and obtaining a rich variety of structural colors. Additionally, a metallic interlayer is introduced to selectively suppress resonances in the short-wavelength region, improving the purity of the red color. The study also investigates the effect of the incidence angle on color purity and transmission efficiency.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Yueqiang Zhao
Summary: Solubility property is of great interest in chemical, physical, pharmaceutical, material, and environmental sciences. Understanding the intrinsic reason behind solubility behavior is a fascinating task. The theoretical relation between binary mutual solubility and liquid-liquid interfacial tension has been derived, where the partitioning of solute molecules between two coexisting liquid phases is determined by the transfer free energy per unit segment for a chain-like solute molecule expressed in terms of solute-solvent interfacial tension. This general theory of solubility is in good agreement with experimental results for binary mutual solubility and molar transfer free energy of solute molecules.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Osama K. M. Bashiar, R. E. Kroon, H. C. Swart, R. A. Harris
Summary: ZnO thin films with near-infrared emission were successfully fabricated using pulsed laser deposition under vacuum conditions, without the need for additional gases or implantation methods. The NIR emission was hypothesized to be caused by defects in the ZnO film due to high energy particle impacts on the sample surface.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
O. Stognei, A. Berezutskii, I. Anisimov, A. Deryabin
Summary: The influence of ZrOn matrix stoichiometry on the electrical and magnetoresistive properties of Fe-Zr-O nanocomposites has been studied. It was found that the magnetoresistive effect is not observed in composites with oxygen lack, while composites with oxygen excess show magnetoresistive effect and increased resistivity. Magnetoresistivity in composites with oxygen lack only appears after heat treatment. These results can be explained by the difference in the density of localized states in the oxide matrix of the composites and the ratio between two types of conductivity.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Mehmet Bayirli, Aykut Ilgaz, Orhan Zeybek
Summary: The present study aims to understand the relationship between impedance characteristics and fractal behaviors. By producing neat and carbon nanotube doped composite specimens, the researchers investigated the electrical properties and surface heteromorphology using Nyquist plots and fractal analysis.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
M. I. Khan, Saddam Hussain, Muhamad Saleem, Fatimah Mohammed Alzahrani, Muhammad Siddique, M. S. Hassan, Allah Ditta Khalid, Munawar Iqbal
Summary: The sol-gel method was used to deposit Ti-doped MAPbBr3 films on FTO-glass substrates with different doping ratios (0%, 4%, and 6%). XRD analysis confirmed the cubic structure of all films, and the 4% Ti-doped film exhibited a large grain size, low band gap energy, and high refractive index. Solar cells fabricated using the 4% Ti-doped MAPbBr3 film showed improved performance in terms of current density, open circuit voltage, fill factor, and efficiency.
PHYSICA B-CONDENSED MATTER
(2024)