Herein, SiO2 nanosheets with thicknesses of 25−100 nm are used to enhance the performance of Au/CdBr2 Schottky barriers. The Au/CdBr2/SiO2/Au straddling‐type heterojunction devices are prepared by the thermal evaporation technique. It is observed that SiO2 layers enhance the crystallinity of CdBr2 through increasing the crystallite sizes and decreasing the defect density, stacking faults, and microstrain by 50%, 56%, 32%, and 34%, respectively. A work function of 6.38 eV is determined from the temperature‐dependent electrical resistivity measurements of p − type CdBr2. In addition, it is observed that, when coated with 50 nm‐thick SiO2, the Au/CdBr2/SiO2/Au straddling‐type transistors can reveal high current rectification ratios of 6.9 × 102 at low biasing voltages in the range of 0.06−0.30 V. The alternating current signals’ analysis in the microwave range of spectra indicates that the current conduction mechanism is dominated by the correlated barrier hopping and quantum mechanical tunneling. It is observed that the Au/CdBr2/SiO2/Au devices exhibit a negative effect accompanied with resonance−antiresonance in the capacitance spectra. Moreover, the microwave cutoff frequency which reaches ≈165.1 GHz and the magnitude of reflection coefficient spectra show that the device under study can perform as multiband pass/stop filters suitable for wire/wireless communication applications including 3G/4G technologies.

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Herein, cadmium bromide thin film devices are designed for possible use in communication technology. The 1.0 m µ thin layer of CdBr 2 is sandwiched between two Au (1.0 m µ thick) layers using the thermal evaporation technique under a vacuum pressure of 10 -5 mbar. The Au/CdBr 2 /Au devices are structurally morphologically and electrically characterized. It is observed that the hexagonal cadmium bromide exhibits large lattice mismatches with cubic Au substrates. The randomly distributed nanorod like grains is accompanied with average surface roughness of ~26 nm. When an ac signal of low amplitude is imposed between the terminals of the Au/CdBr 2 /Au devices, a negative capacitance effect in the frequency domain of 10-1800 MHz is observed. In addition, analysis of the impedance spectra in the same domain has shown that the device behaves as band pass/stop filters suitable for 4G technology. The microwave based standard analysis of the Au/CdBr 2 /Au band filters have shown that it displays a notch ( co f ) frequency of 2.0 GHz. The cutoff frequency at co f reaches 7.86 GHz. The features of the Au/CdBr 2 /Au devices nominate it for use as microwave resonators and as negative capacitance devices suitable for; 4G technology, noise reduction and for parasitic capacitance cancellation.

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