CO2 detection using Al/Si Schottky diode by IR spectroscopic technique

In this study, utility of aluminum-silicon (Al/Si) Schottky diode is demonstrated as an optical detector of carbon dioxide (CO
₂
) in NIR (1.57 and 1.60 μm) region. For this purpose, a self-fabricated Al/Si Schottky diode (barrier height 0.71 eV) and a broad band infrared irradiation source were used. An acrylic sheet were used to filter higher wavelength irradiation. Schottky diode was fabricated by depositing aluminum on patterned n-silicon (resistivity 0.2-0.4 Ω-cm) by thermal evaporation technique. Presence of CO
₂
between the detector and the irradiation source showed decrease in reverse bias current up to 15 %. It is proposed that the demonstrated technique can be successfully employed in real time applications involving CO
₂
detection.