An ion-implanted Ga(AsP)/GaP strained-layer superlattice photodetector

We present the wavelength and spatially dependent photoresponse of the first ion-implanted strained-layer superlattice (SLS) photodiodes. Devices were formed by Be+ implantation of GaAs0.15P0.85/GaP SLS´s followed by controlled-atmosphere annealing. Spatial response of the devices is uniform to within 3 percent when probed by a laser spot of 4.4 µm diam, while the wavelength-dependent photoresponse is characteristic of SLS´s in this material system. Although not fully optimized, the devices exhibit uncoated peak external quantum efficiencies of 30 percent. These results demonstrate that ion-implanted SLS´s can perform as useful detectors while retaining the desirable properties of the as-grown strained-layer superlattice.