La/Ge stacked nanosheets designed as optical resonators, microwave oscillators and 5 G/6 G gigahertz receivers

Glass/Ge and La/Ge stacked layers, 100 nm thick, were prepared via thermal evaporation under a vacuum pressure of 10−5 mbar. Structural analysis confirmed amorphous growth of Ge nanosheets. Optically coating Ge onto La improved light absorption, energy band gap, and dielectric responses. In addition, dielectric spectra fitting using Lorentz approach showed increased free electron density, plasmon frequency, and drift mobility (up to 1153 cm2/Vs) in Ge due to lanthanum presence. Moreover, LGA Schottky barrier devices (La/Ge/Au) exhibited tunneling-type current conduction with 0.815 eV barrier height and 40 nm width. Resistance spectra of these Schottky barriers displayed negative resistance near 0.40 GHz, while capacitance spectra showed resonance-antiresonance behavior. La/Ge and LGA interface can be utilized for optical receivers and microwave resonators in 5 G/6 G technologies.