Miniaturized InSb Mid-JR Sensor for Room Temperature Operation

This paper reports the development and evaluation of an InSb photovoltaic infrared sensor (InSb PVS) operating at room temperature. The InSb PVS consists of 700 InSb p⁺-p^--n⁺ photodiodes connected in series, on a semi-insulating GaAs (100) substrate. An Al_0.17In_0.83Sb barrier layer between p⁺ and p^- layers was used to reduce diffusion of photo-excited electrons. Cutoff wavelength was 6.8 mum and output signal was linear with incident irradiance. Noise equivalent temperature difference (NETD) of 2.2times10^-3 degC/Hz^1/2 was obtained at room temperature, which shows the sensor to be a promising device for human body detection or non-contact thermometry.