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The energy dissipation characteristics of the non-linear normal vibration contact system of the interface have important theoretical and engineering significance for describing the dynamic mechanism of the interface.Based on Hertz contact theory, the dynamic model of nonlinear normal vibration contact of damping joint interface is established, and the dynamic response of damped free vibration and simple harmonic forced vibration and the calculation method of vibration contact energy dissipation are proposed; the non-linearity is established The dynamic equation of the normal vibration contact system, the energy dissipation rate and cumulative energy dissipation rate of damped free vibration, and the input energy and damping loss energy of simple harmonic forced vibration are calculated; the nonlinear normal vibration contact interface is studied The relationship between energy dissipation characteristics and energy transfer provides a theoretical basis for describing the dynamics of the vibrating contact interface.

The development of high-quality GaN-based heterojunctions breaks through the limitation of lattice mismatch, which is of particular importance for promoting their optoelectronic applications. Herein, we report the incommensurate heteroepitaxial growth of single-crystal cesium lead iodine (CsPbI3) nanoplatelets on a c-GaN/sapphire substrate with a uniform rectangular shape and composition distribution via one-step chemical vapor deposition. The formed CsPbI3/GaN heterojunction presents a type-II band alignment with the valence and conduction band offsets of 2.12 ± 0.15 eV and 0.60 ± 0.15 eV, respectively. Compared with CsPbI3 grown on a mica substrate, the CsPbI3/GaN heterojunction exhibits remarkable photoluminescence quenching and a shorter exciton lifetime, which arises from the enhanced carrier separation and extraction efficiencies induced by the band-offset effect. Thanks to the complementarity between the band gaps of CsPbI3 and GaN, the optical absorption of the formed heterojunction is expanded from the visible light to ultraviolet. These findings suggest the large potential of the CsPbI3/GaN heterojunction for the development of high-performance integrated photovoltaic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Monolayer transition metal dichalcogenide (TMD) alloys with tunable band gaps exhibit huge potential in nanoelectronics, optoelectronics, and photonics. The scalable production of uniform atomically thin TMD alloys is a key step for the realization of their device applications but remains a large challenge so far. Here, we report oxygen-assisted chemical vapor deposition (CVD) of uniform atomically thin MoS2(1–x)Se2x semiconductor alloys via a vertical Mo-precursor supply strategy. The growth scheme leads to the formation of highly crystalline MoS2(1–x)Se2x monolayer films within a short growth time of 8 min, which benefits from a stable and homogeneous Mo-precursor feeding environment and the synergic effect of NaBr and oxygen carrier on the growth. The high-resolution spectral characterizations and density functional theory calculations demonstrate that the chemical composition of the as-grown MoS2(1–x)Se2x monolayers can be continuously tuned from x = 0 to 1, leading to the corresponding band gap being gradually changed from 1.81 to 1.55 eV. This work provides an efficient strategy to obtain large-area uniform MoS2(1–x)Se2x monolayer alloys with tunable compositions and optical properties, which is essential for driving their applications in various functional optoelectronic devices, especially for high-performance flexible photodetectors. [ABSTRACT FROM AUTHOR]