Spatially resolved photoresponse in both lateral and vertical directions of InGaAs photodetector

In planar photodetectors, light absorption and charge carrier collection occur approximately 1–5 μm beneath the surface. This makes it difficult to resolve the spatially resolved photoresponse of the detector under operating conditions. In this study, laser beam induced current combined with a precision cleavage technique is employed to investigate the photoresponse characteristics in both the lateral and vertical directions of planar InGaAs PIN detectors, allowing for detailed extraction of the PN junction profile, photocurrent distribution, and minority carrier diffusion length before and after rapid thermal annealing. This combined technique provides a path for exploring the spatial distribution and transport properties of photogenerated carriers in planar detectors under operating conditions.