Analysis of Complex Electromagnetic Structures by Hybrid FDTD/WCIP Method

This paper proposes a hybrid full-wave analysis using Finite-Difference Time-Domain (FDTD) and Wave Concept Iterative Process (WCIP) methods, developed to analyze locally arbitrarily shaped microwave structures and Multilayer Planar structure. Using the equivalence principle, the original problem can be decomposed into two sub regions and solve each sub region separately. An interpolation scheme is proposed for communicating between the FDTD fields and WCIP wave, which will not require the effort of fitting the WCIP mesh to the FDTD cells in the interface region. This method is applied to calculate the scattering parameters of arbitrary (3-D) microwave structures. Applying FDTD to 3D discontinuity and WCIP to the remaining region preserves the advantages of both WCIP flexibility and FDTD efficiency. A comparison of the results with the FDTD staircasing data verifies the accuracy of the proposed method.

High-response formamidine bromide lead hybrid cadmium sulfide photodetector

Organic-inorganic hybrid perovskite formamidinium lead bromide nanosheet(FAPb Br_(3)NS)is regarded as a superior substance used to construct optoelectronic devices.However,its uncontrollable stability seriously affects its application in the field of photodetectors.In this paper,FAPb Br_(3)is combined with cadmium sulfide nanobelt(Cd S NB)to construct a hybrid device that greatly improves the stability and performance of the photodetector.The response of the FAPb Br_(3)NS/Cd S NB detector under 490 nm light illumination reaches 5712 A/W,while the response of the FAPb Br_(3)photodetector under equivalent conditions is only 25.45 A/W.The photocurrent of the FAPb Br_(3)NS/Cd S NB photodetector is nearly 80.25%of the initial device after exposure to air for 60 days.The difference in electric field distribution between the single material device and the composite device is simulated by the finite-difference time-domain method.It shows the advantages of composite devices in photoconductive gain and directly promotes the hybrid device performance.This paper presents a new possibility for high stability,fast response photodetectors.