Effect of lanthanum substrates on the structural, optical and electrical properties of copper selenide thin films designed for 5G technologies

Abstract

In this work, copper selenide thin films coated onto glass and transparent lanthanum substrates are studied. The (glass, La)/CuSe thin films which are prepared by the thermal evaporation technique under a vacuum pressure of 10 -5 mbar are structurally, morphologically, optically, dielectrically and electrically characterized. Lanthanum substrates improved the crystallinity by increasing the crystallite size and decreasing both of the microstrains and defect density of copper selenide. La substrates redshifts the energy band gap and doubled the dielectric constant values. In addition, employing Drude-Lorentz approaches for optical conduction to fit the dielectric constant provided information about the effects of La substrates on the drift mobility, plasmon frequency, free carrier density and scattering times at femtosecond level. The drift mobility increased and the plasmon frequency range is modified when La substrates are used. Verifying impedance spectroscopy test in the microwave frequency domain have shown that the La(gate)/CuSe/Ag (source) transistors can be employed as band pass filter suitable for 5G technologies. The microwave cutoff frequency reached ~5.0 GHz at a notch frequency of 2.80 GHz of the La/CuSe/Ag highpass filters.

Pt/SeO2 optical receivers designed for terahertz and 5G/6G technologies

“…The plasmon frequency of the IR oscillator increased from 0.64 GHz to 5.81 GHz and 6.50 GHz when Pt layer of thickness of 10 and 50 nm forces plasmonic interactions. The value of the plasmon frequency in the presence of Pt is promising for 5G technology as it exhibits values comparable to the cutoff frequencies of 5G technology resonators [28,29]. It is also worth noting that the free carrier density in the presence of Pt plasmonic particles reaches the order of 10 19 cm −3 .…”

Growth and Characterization of Lanthanum Germanide Thin Films by the Thermal Evaporation Technique

“…[ 46 ] In addition, hydrogen‐ terminated diamond field‐effect transistors which uses LaB 6 as gate material showed a current switching property with “ON/OFF” ratio that reaches nine orders of magnitude and effective mobility of 195.4 cm 2 V −1 s −1 . [ 47 ] In that sector as a dielectric thin films L 2 O 3 /ZrO 2 employed as gate dielectric in Ge Schottky barrier p‐metal–oxide‐semiconductor‐field effect transistors (MOSFET) increased the current “ON/OFF” ratio in the FETS from 10 2 to 10 4 . [ 48 ] These examples should direct the attention toward future studies which include possible application of La 6 Ge in thin film transistor technology.…”