Noise performance of InGaAs-InP quantum-well infrared photodetectors

Dark current noise measurements were carried out between 10 and 10/sup 4/ Hz at T=80 K on two InGaAs-InP quantum-well infrared photodetectors (QWIPs) designed for 8-/spl mu/m infrared (IR) detection. Using the measured noise data, we have calculated the thermal generation rate, bias-dependant gain, electron trapping probability, and electron diffusion length. The calculated thermal generation rate (/spl sim/7/spl times/10/sup 22/ cm/sup -3//spl middot/s/sup -1/) is similar to AlGaAs-GaAs QWIPs with similar peak wavelengths, but the gain is 50/spl times/ larger, indicating improved transport and carrier lifetime are obtained in the binary InP barriers.