The transport and photoelectric properties of four two-dimensional (2D) silicene/MX 2 (M = Mo, W; X = S, Se) heterostructures have been investigated by employing density functional theory, nonequilibrium Green’s function, and Keldysh nonequilibrium Green’s function methods. The stabilities of silicene (SiE) are obviously improved after being placed on the MX 2 (M = Mo, W; X = S, Se) substrates. In particular, the conductivities of SiE/MX 2 are enhanced compared with free-standing SiE and MX 2 . Moreover, the conductivities are increased with the group number of X, i.e., in the order of SiE < SiE/MS 2 < SiE/MSe 2 . An evident current oscillation phenomenon is observed in the SiE/WX 2 heterostructures. When a linear light illumination is applied, SiE/MSe 2 shows a stronger photoresponse than SiE/MS 2 . The maximum photoresponse with a value of 9.0 a 0 2 /photon was obtained for SiE/WSe 2 . More importantly, SiE/MS 2 (M = Mo, W) heterostructures are good candidates for application in designing solar cells owing to the well spatial separation of the charge carriers. This work provides some clues for further exploring 2D SiE/MX 2 heterostructures involving tailored photoelectric properties.

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In this article, a reconfigurable frequency selective surface (RFSS) with a wide reconfigurable passband and angular stability property is proposed. In this design, The RFSS consists of three metallic layers and two thin dielectric substrates with metallic via holes. Tunable electromagnetic characteristics are achieved by loading varactor diodes. Because of the symmetry of the structure and the insertion of metal via holes, the RFSS is insensitive to the incidence of TE and TM polarization, thus improving angular stability. The proposed RFSS can be tuned from 5.4 to 15.96 GHz when the incident angle ranges from 0° to 60°. The RFSS was made and tested to verify the proposed design. The proposed RFSS has good performances, which are verified by simulation and measurement results.

This paper focuses on designing dichroic filters for changing the color of light-emitting diode (LED) lamps. Dichroic filters are composed of multiple dielectric layers on a substrate. By applying a dichroic filter, some of the LED's spectral energy is reflected and some is transmitted, which changes the lamp's color. Conventional methods to obtain spectral transmittance curves have shortcomings. The design criteria for the transmittance curves are incompatible with the metrics used in lighting applications, such as correlated color temperature (CCT) and color rendering index (CRI). Thus, the color rendering performance and the optical transmission of a lighting system are not optimized. This observation leads to the development of a proposed method for designing dichroic filter transmittance curves to provide accurate color shift, high CRI, and sufficient optical transmission. The method initially uses the transmittance curve of an existing color filter that provides a roughly close color shift for the LED lamp to calculate the transmittance curve that causes an accurate color shift by polynomial approximation. Based on the approximated curve, a preliminary transmittance curve without the effect of the LED lamp's secondary optics is derived and verified in thin-film design and optical design software tools. Further, the derived preliminary transmittance curve is optimized by applying an algorithm to loop through a large amount of representative curves fluctuating near the preliminary curve. The resulting dichroic filter provides an accurate color shift (ΔCCT = -800±50K, Duv = ±0.003), high CRI (Ra and R9 >= 95), and sufficient luminous flux transmission (>= 70%).