We develop a simple new design for a multi-band metamaterial absorber (MTMA) for radar applications. Computer Simulation Technology (CST) Studio Suite 2018 was used for the numerical analysis and absorption study. The simulated results show four high peaks at 5.6 GHz, 7.6 GHz, 10.98 GHz, and 11.29 GHz corresponding to absorption characteristics of 100%, 100%, 99%, and 99%, respectively. Furthermore, two different structures were designed and compared with the proposed MTMA. The proposed structure remained insensitive for any incident angle and polarization angle from 0° to 60°. Moreover, negative constitutive parameters were retrieved numerically. To support the simulated results, the proposed design was fabricated by using a computer numerical control-based printed circuit board prototyping machine and tested experimentally in a microwave laboratory. The absorption mechanism of the proposed MTMA is presented through the surface current and electric field distributions. The novelties of the proposed structure are a simple and new design, ease of fabrication, low cost, durability, suitability for real-time applications and long-term stability given the fabrication technique and non-destructive measurement method and very high absorption. The proposed structure has potential applications in C and X band frequency ranges.

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In this work the performance of organic field‐effect transistors (OFETs) using Copper Phthalocyanine (CuPc) and Titanyl Phthalocyanine (TiOPc) as active layers is compared. Current/Voltage measurements were first performed in vacuum and later under ambient conditions. The highest hole mobility μvac = (1.5 ± 0.6) × 10–3 cm2/Vs was obtained for the CuPc OFETs. The mobility remained constant within the error bar after exposing the OFETs to atmosphere (μatm = (1.2 ± 0.2) x 10–3 cm2/Vs). For the TiOPc transistors a hole mobility of μvac = (7.2 ± 4.0) × 10–5 cm2/Vs was found in vacuum. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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The efficiency of dye-sensitized solar cell (DSSC) has been improved by various ways. In this work, The CdS nanoparticles were added in the TiO2 working electrode for improving the efficiency of DSSC. The DSSC structure comprises of TiO2 working electrode with and without CdS powder, Pt counter electrode, rutherium (II) (N719) dye and lithium iodide electrolyte. Normally, the TiO2 paste was screened for five layers. In this work, the TiO2 paste with CdS nanoparticles was screened for various numbers of layers on the layers of pure TiO2 to get the total of five layers. Then TiO2 mixed and unmixed CdS nanoparticles and Pt films were annealed at the temperature of 500°C for 50 min. Impedance spectroscopy (IS) was used to study charge transport in each interface of DSSC. For illumination condition, the measured IS can be divided into three regions that were charge transport at Pt layer, charge transport at working electrode/dye/electrolyte interface and ion contribution at electrolyte layer. The carrier transport parameters extracted from fitting IS spectra were chemical capacitance, charge transfer resistance and time constant.