A completely asymmetrical dual-band micro-strip filter combined with a complementary split ring resonator (CSRR) consisting of a circle and a square, and substrate integrated waveguide (SIW) is presented in this paper. The proposed design can be applied in the Industrial Scientific Medical (ISM) band. The CSRR of this completely asymmetrical filter, which has both square and circular parts, can realize two distinct passbands and shows higher out-of-band rejection than symmetrical filters; it is an asymmetrical complementary split ring resonator (ACSRR). The out-ofband rejection level between two passbands can reach 40 dB, compared to 35 dB in a circular filter and 30 dB in a square filter. The measured results are in good agreement with simulated results. key words: asymmetrical complementary split ring resonator (ACSRR); substrate integrated waveguide (SIW); dual-band filter; high out-of-band rejection Classification: Microwave and millimeter wave devices, circuits, and hardware

All-inorganic halide semiconductors with perovskite or perovskite-like structure have aroused a widespread concern recently for its environmental friendliness and stabilities while possessing excellent optoelectronic properties. Double perovskite Cs2AgBiBr6 single crystal (SC) is one of the most representative materials in the latest research area. To further improve the device response range and decrease its dark current density effectively, functional layers based on the solution-processed epitaxial method are normally fabricated as heterojunctions. Herein, a novel idea of a broadband heterojunction MAPbI3 (MA = CH3NH3)/Cs2AgBiBr6 is proposed in this work to achieve this goal. A MAPbI3 layer is fabricated on Cs2AgBiBr6 SC substrates through immersing Cs2AgBiBr6 SC into MAPbI3 solution at a MAPbI3 crystallization temperature. Ultimately, this heterojunction device expands the absorption limit from 618 to 838 nm, makes responsivity range redshift from 629 to 860 nm, and achieves a responsivity of 16.8 mA W−1 while the detectivity of 1.33 × 1011 Jones under 622 nm 0.55 mW cm−2 illumination at −20 V bias, maintaining excellent optoelectronic properties.

Low-cost, handily prepared, and efficient large-scale triboelectric nanogenerator (TENG) is considered as the new scheme for distributed mechanical conversion or renewable blue energy utilization. Semiconductors with high carrier mobility introduction potency overcome pure polymer restriction for uncompetitive short current density. An extremely popular all-inorganic lead-free double perovskite Cs2AgBiBr6 (CABB) has emerged as extraordinary potential material in the substitution of semiconductor triboelectric material, which overcomes the limitations of high impedance associated with organic polymer insulator-based materials. In this current study, assembled by CABB which was certified as an available positive frictional material, TENG with a sandwiched structure of ITO/c-TiO2 (compact TiO2)/m-TiO2 (mesoporous TiO2)/CABB - the poly tetra fluoroethylene (PTFE)/Al exhibits appropriate performance on environmental stability and output capacity. A comparison of the fabrication process showed that spraying is an inexpensive method to prepare large-scale functional films of CABB TENG with brilliant relative dielectric constant and work function (Wf) difference that possess more distinguished output characteristics. This was confirmed by the appearance of higher open-circuit voltage of 105 V, larger short-current density of 2.45 mA/m2 at 0.25 Hz motion parameter, and more abundant power density output of 0.76 W/m2 under a higher frequency of 10 Hz. Further study clearly confirmed that both higher frequency and larger contact area are conducive to the total output power, while terminal charging speed is inversely or positively proportional with capacitance or mechanical frequency. The final physical display effect showed that spraying with CABB TENG could light up at least 53 commercial yellow LEDs, holding decent energy conversion ability. This confirms its efficiency, high throughput, and cost efficiency.