A multispectral radiation detector for detecting radiation in at least two spectral bands, comprises a substrate and a layer stack grown on the substrate. The layer stack comprises at least first and second photodiodes, each photodiode having at least one strain-compensating superlattice absorbing layer substantially lattice matched to adjacent layers of the detector. Each strain-compensating superlattice absorbing layer has an energy gap responsive to radiation energy in a corresponding spectral region and different from the energy gaps of other strain-compensating superlattice absorbing layers of the detector.