Influence of Ge Concentration and Deposition Temperature on the Photoresponse Characteristics of Ge:SiO₂ Nanocomposite Thin Films

This study examines the opto-electric characteristics of Ge:SiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> composite films produced via magnetron sputtering at substrate temperatures of 300°C, 400°C, and 500°C, with varying Ge concentrations. We employed x-ray diffraction, current-voltage measurements, and spectral photocurrent analysis to investigate the films structural, optical, and opto-electrical properties. Illumination of the samples resulted in a marked increase in current compared to dark conditions. Spectral photocurrent measurements revealed cutoff wavelengths of 1300 nm for films with 25:75 vol% Ge:SiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> ratio, extending to 1320 nm for compositions with higher Ge content (60:40 vol%). These findings align with observations from I-V curve analyses. Our research highlights the potential of Ge:SiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> composites for enhancing optoelectronic device performance. The results underscore the importance of continued investigation and innovative applications in this field to drive technological advancements.