The temperature-dependent photoresponse uniformity of an InGaAs subpixels infrared detector by the LBIC technique

Abstract

The front-illuminated InP/InGaAs/InP PIN hetero-junction photovoltaic subpixels infrared detector has been achieved based on the lateral collection effect of photogenerated carriers. The photoresponse uniformity of the detector is carried out with a LBIC technique at different temperatures between 88 K and 296 K. With the aid of LBIC and the scanning capacitance microscopy (SCM) technique, the holes diffusion length L p related to temperature was obtained. The result shows that the photoresponse uniformity decreases with temperature dropping, and L p also varies directly in proportional to √ T . The acoustic phonon scattering is the chief scattering mechanism existing in the detector with doped InGaAs (n ≈ 5 × 10 16 cm −3 ) in the measured temperature range. The LBIC technique can be utilized effectively in the measurement of photoresponse uniformity of InGaAs infrared detectors, especially for the InGaAs subpixels detectors.