Structural, Optical and Electrical Properties of Band‑Aligned CdBr2/Au/ Ga2S3 Interfaces and Their Application As Band Filters Suitable for 5G Technologies

Abstract

Herein, the structural, optical and electrical properties of band-aligned CdBr2/Ga2S3 interfaces in the presence and absence of Au nanosheets (10-20 nm) as interface spacers are reported. CdBr2/Au/Ga2S3 (CAG) stacked layers are grown by vacuum evaporation under a vacuum pressure of 10-5 mbar. It is observed that coating of amorphous Ga2S3 onto CdBr2 increases the crystallite size and decreases the microstrain, defect density and stacking faults in hexagonal CdBr2. Depositing Ga2S3 onto CdBr2 enhanced the light absorbability of Ga2S3 by more than 120 times. Insertion of Au nanosheets as spacers between the Ga2S3 and CdBr2 layers highly engineered the energy band gap of the CAG structure. In addition, the frequency-dependent capacitance, conductance and impedance spectroscopy analyses in the microwave frequency domain have shown the abil ity of the CAG structure to reveal negative capacitance efect and the ability to behave as microwave resonators displaying controllable (by Au nanosheets) resonance-antiresonance phenomena. CAG bilayers showed microwave band pass/reject characteristics with tunable and multiband features. The microwave cutof frequency at the notch frequency of the band flters are found to suitable for the 5G mobile technologies