Investigation of Electromagnetic Interference Shielding Effectiveness of CZ Grown Ge Optical Windows

Abstract

In this study, different Ge IR optical windows are produced and their electromagnetic interference (EMI) shielding performances are investigated. Three Ge single crystals with different doping concentrations are grown by the Czochralski (CZ) technique. Optical windows are obtained after the slicing, lapping, and polishing processes are examined. Formation of (111)-oriented single crystal is observed from the X-ray diffraction (XRD) pattern. In addition, IR transmission of the crystals is measured around 45% in the range of 2-12 µm using Fourier transform infrared spectrometer (FTIR) spectrometer. EMI shielding effectiveness (SE) of the windows is determined in a flanged coaxial SE tester developed for outer diameter as 1 inch. SE results are evaluated by taking into account both resistivity, thickness of the samples and limitations of measurement fixture.

Synthesis and characterization of nanostructured Ge/GeO2 films using spin coating technique

“…Both Si and Ge are indirect bandgap semiconductors with bulk bandgaps of 1.11 eV and 0.66 eV at room temperature [1,2]. Si being economical and abundantly available [3] have been used in large amounts in diodes [4], semiconductor processors [4], commercial photovoltaic panels [5] while Ge has seen relatively small demands in wide range of more sophisticated and efficiency-driven application like transistors [2], satellite solar cells [6], fast switching diodes [7], infrared optics [8], electromagnetic shielding [9], thermal imaging sensors [10], and solid-state electronic devices [11,12]. This wide range of Ge based application is due to its high electrical conductivities [13] and highly tunable band gap through quantum confinement effects [14].…”

“…Previously, Ge thin films have been developed using chemical vapor deposition (CVD) [9], atomic layer epitaxy [19], thermal evaporation [20], ion beam [21] and electron beam evaporation techniques [22]. Among them, S Mathur et al reported core/shell Ge wires synthesized through CVD using Ge(C 2 H 5 ) 2 [2].…”