Anomalous thermal behaviors of excitonic luminescence in CsPbBr perovskite quantum dots (PQDs) were observed. It is found that the main luminescence peak originated from the excitonic radiative recombination assisted by the longitudinal-optical (LO) phonon, and its integrated intensity first declines as the temperature varies from 10 to 150 K and then turns to increase at ∼160 K, reaching a maximum value at 300 K. A model considering the thermal detrapping and transfer of electrons from a trap level is developed to interpret these abnormal thermal behaviors of the luminescence from the PQDs.
View Article and Find Full Text PDFMicromachines (Basel)
September 2024
A multi-function sensor based on an all-dielectric metastructure for temperature and refractive index sensing simultaneously is designed and analyzed in this paper. The structure is composed of a periodic array of silicon dimers placed on the silicon dioxide substrate. By breaking the symmetry of the structure, the ideal bound states in the continuum can be converted to the quasi-bound states in the continuum, and three Fano resonances are excited in the near-infrared wavelength.
View Article and Find Full Text PDFFano resonance with high Q-factor is considered to play an important role in the field of refractive index sensing. In this paper, we theoretically and experimentally investigate a refractive index sensor with high performance, realizing a new approach to excite multiple Fano resonances of high Q-factor by introducing an asymmetric parameter to generate a quasi-bound state in the continuum (BIC). Combined with the electromagnetic properties, the formation mechanism of Fano resonances in multiple different excitation modes is analyzed and the resonant modes of the three resonant peaks are analyzed as toroidal dipole (TD), magnetic quadrupole (MQ), and magnetic dipole (MD), respectively.
View Article and Find Full Text PDFWe have designed and analyzed the high quality-factor (Q-factor), multiple Fano resonances device on the basis of the all-dielectric metastructure. The unit structure consists of two rectangular air holes etched within a silicon cube and periodically aligns on the substrate of silicon dioxide. The results demonstrate that four Fano resonances are achieved by integrating the theory of bound states in the continuum (BIC)and breaking the symmetry (width symmetry or depth symmetry) of two rectangle air holes, and the resonant wavelength can be modified by altering structural parameters.
View Article and Find Full Text PDFWe study the totally asymmetric simple exclusion process on multiplex networks, which consist of a fixed set of vertices (junctions) connected by different types of links (segments). In particular, we assume that there are two types of segments corresponding to two different values of hopping rate of particles (larger hopping rate indicates particles move with higher speed on the segments). By simple mean-field analysis and extensive simulations, we find that, at the intermediate values of particle density, the global current (a quantity that is related to the number of hops per unit time) drops and then rises slightly as the fraction of low-speed segments increases.
View Article and Find Full Text PDFHybrid integrated photodetectors with flat-top steep-edge spectral responses that consist of an Si-based multicavity Fabry-Perot (F-P) filter and an InP-based p-i-n absorption structure (with a 0.2 μm In(0.53)Ga(0.
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