Development of uncooled miniaturized InSb photovoltaic infrared sensors for temperature measurements

Abstract

This paper reports the development of an InSb photovoltaic infrared sensor (InSb PVS) operating at room temperature for temperature measurements. The InSb PVS consists of 910 InSb p +–p −–n + photodiodes connected in series on a semi-insulating GaAs (1 0 0) substrate. An Al 0.17In 0.83Sb barrier layer was grown between the p + and p − layers to reduce the diffusion of photo-excited electrons. As the InSb PVS operates in a photovoltaic mode, no thermal insulation is required, enabling its miniaturized plastic molding package. The sensitivity of the InSb PVS was 127 μV/K, and a noise equivalent temperature difference (NETD) of 1.0 mK/Hz 1/2 was obtained at room temperature. The results demonstrate the potential for the sensor to be used both in non-contact thermometry, as well as human body detection.