Uncooled InGaSb photovoltaic infrared detectors for gas sensing

Abstract We developed a mid-infrared InGaSb-based photovoltaic infrared sensor (InGaSb PVS) for gas sensing, with improved performance at room temperature, when compared with previous InSb-based PVS. To improve the performance at absorbance wavelengths of most important gases, such as CO 2 , InGaSb was employed in the light absorber layer. High quality InGaSb films were obtained with the introduction of an InSb buffer layer, directly grown on GaAs substrate. As a result, the signal-to-noise ratio (SNR) of the InGaSb PVS was 1.3 times higher than the previous InSb PVS at a wavelength of 4.2 μm, were CO 2 absorption occurs.