Novel infrared phototransistors for atmospheric CO/sub 2/ profiling at 2 /spl mu/m wavelength

Two-micron detectors are critical for atmospheric carbon dioxide profiling using the lidar technique. The characterization results of a novel infrared AlGaAsSb/ InGaAsSb phototransistor are reported. Emitter dark current variation with the collector-emitter voltage at different temperatures is acquired to examine the gain mechanism. Spectral response measurements resulted in responsivity as high as 2650 AAV at 2.05 /spl mu/m wavelength. Bias voltage and temperature effects on the device responsivity are presented. The detectivity of this device is compared to InGaAs and HgCdTe devices.