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The electronic states of fullerene structures are modulated by external environments, such as magnetic fields, electric fields, and stress, which exhibit unique physical properties. Compression, i.e., the application of compressive stress to fullerene structures, plays an important role in modulating the optoelectronic properties of fullerene materials. Herein, we comprehensively investigate the stability, band structures, Bloch wave functions, and optical responses of two-dimensional quasi-tetragonal phase C60 (qTP C60) and quasi-hexagonal phase C60 (qHP C60) under external stress. The findings reveal that qTP C60 and qHP C60 can be stabilized within a certain range based on the regulation of external stress. This kind of stress can considerably alter the band structures of qTP C60 and qHP C60, thereby changing the positions of the highest occupied and lowest unoccupied molecular orbitals. The analysis of Bloch wave functions can help visualize the electronic density distribution of qTP C60 and qHP C60 structures, indicating a considerable influence of stress on the electronic state distribution of the system. This influence results in changes in the band structure, thus affecting the electronic distribution state and optical response. Furthermore, qTP C60 and qHP C60 exhibit surface plasmon effects within a specific wavelength range, suggesting their potential applications in optoelectronic devices. [ABSTRACT FROM AUTHOR]

In this article, the linear and nonlinear optical properties of in-plane lateral MoSe2–WSe2 heterostructures are theoretically investigated. The polarization-dependent strongest optical absorption in one-photon absorption occurs in charge transfer excited states, where electrons transfer from WSe2 to MoSe2. This phenomenon is supported by the LUMO (lowest unoccupied molecular orbital) and HUMO (highest occupied molecular orbital) imaging obtained through scanning tunneling microscopy. The charge difference density and transition density matrix are used to interpret the electronic transitions, and these interpretations rely on the concept of transition density. The optical properties of two-photon absorption in its nonlinear optical process are significantly different from the excitation in one-photon absorption, where the strongest optical absorption is contributed from direct transition from the ground state to the final state without going through an intermediate excited state, due to the very large difference of permanent dipole moments between the excited and ground states. Our results also reveal directional fluorescence and physical mechanism of in-plane lateral MoSe2–WSe2 heterostructures. Our work can provide insights into the physical mechanism of the optical properties of in-plane lateral MoSe2–WSe2 heterostructures. [ABSTRACT FROM AUTHOR]

Flexible pressure sensors based on micro‐/nanostructures can be integrated into robots to achieve sensitive tactile perception. However, conventional symmetric structures, such as pyramids or hemispheres, can sense only the magnitude of a force and not its direction. In this study, a capacitive flexible tactile sensor inspired by skin structures and based on an asymmetric microhair structure array to perceive directional shear force is designed. Asymmetric microhair structures are obtained by two‐photon polymerization (TPP) and replication. Owing to the features of asymmetric microhair structures, different shear force directions result in different deformations. The designed device can determine the directions of both static and dynamic shear forces. Additionally, it exhibits large response scales ranging from 30 Pa to 300 kPa and maintains high stability even after 5000 cycles; the final relative capacitive change (ΔC/C0) is <2.5%. This flexible tactile sensor has the potential to improve the perception and manipulation ability of dexterous hands and enhance the intelligence of robots. [ABSTRACT FROM AUTHOR]

Environmental pollution caused by organic pollutants has been attracted more and more attention by the researchers. In this paper, ZnIn2S4 modified TiO2 nanotube array (ZnIn2S4/TiO2) composite electrodes are prepared by loading chalcogenide semiconductor material ZnIn2S4 on the surface of TiO2 nanotube array (TiO2 NTA) for the degradation of methylene blue (MB). The physicochemical properties of ZnIn2S4/TiO2 composite electrodes are analyzed by X-ray photoelectron spectroscopy, X-ray diffraction, photoluminescence spectroscopy and so on. The photoelectrocatalytic degradation rate of ZnIn2S4/TiO2 composite electrode with the concentration of ZnIn2S4 as 0.5 mmol/L (ZISTO-2) reaches 93.3% under the bias voltage of 0.7 V and simulated sunlight irradiation for 180 min against MB, which is 22.44% higher than that of pure TiO2 NTA electrode, and the degradation rate of ZISTO-2 composite electrode toward MB is maintained at 78.2% after five cycles. The radical trapping experiments indicate that h+, ·O2− and ·OH has significant contribution in the photoelectrocatalytic degradation. This paper provides a new ideal way to solve the problem of water pollution under visible light. [ABSTRACT FROM AUTHOR]

An external electric field can change the electronic and band structures of 2D nanomaterials, thereby regulating their physical properties and nanodevice functions. In this study, the anisotropy of the nanomaterials quasi-tetragonal phase C60 (qTP C60) and quasi-hexagonal phase C60 (qHP C60) under an applied electric field was theoretically evaluated. We investigated the physical mechanisms underlying the changes in the band structure, optical response, Bloch wave function, and electronic structure of the 2D qTP C60 and qHP C60 systems under an applied electric field. Our findings reveal that an external electric field can considerably shift the valence and conduction band positions within the band structure. Notably, qTP C60 and qHP C60 display remarkable stability and can only transition from a semiconducting state to a conducting state under specific external electric-field intensities. Visualization of the electron density distribution via Bloch wave function analysis of the qTP C60 and qHP C60 structures showed dominant influence of the external electric field on the structures and configurations of these systems. Because of such perturbations, the energy band structure changes, affecting the electron distribution and optical response. Additionally, qTP C60 and qHP C60 exhibit a surface plasmon effect within a specific wavelength range and can thus be used in photoelectric amplification nanodevices. Overall, our calculations provide a theoretical foundation for the application of qTP C60 and qHP C60 in the field of photoelectricity and promote the development and application of fullerene-based materials in the fields of energy storage, optoelectronics, and quantum nanodevices. [ABSTRACT FROM AUTHOR]