Theoretical analysis of room temperature InAs/sub 0.89/Sb/sub 0.11/ mid-infrared (MIR) photodetector for CO detection

A complete theoretical model of a mid-infrared double heterostructure photodetector has been developed. The model is physics based one and takes into account all the dominant mechanisms that shape the characteristics of room temperature MIR detectors. In this paper the detectivity, V-I characteristics and photo-response of an InAs/sub 0.55/Sb/sub 0.15/P/sub 0.30//InAs/sub 0.89/Sb/sub 0.11//InAs/sub 0.55/Sb/sub 0.15/P/sub 0.30/ double heterostructure mid-infrared photodetector have been analyzed. This photodetector has an extended spectral response (2.5 /spl mu/m to 5.0 /spl mu/m) as compared to other currently available III-V room temperature detectors. The maximum detectivity of 1.18/spl times/10/sup 7/ mHz/sup 1/2/ W/sup -1/ and responsivity of 0.83 A/W are obtained near cut-off wavelength at 5 /spl mu/m. This device could be used as an optical sensor for the environmental monitoring of carbon monoxide.