Ion-implanted strained-layer superlattice device

High-quality p-n junction diodes are demonstrated in Be⁺-implanted GaAsxP1-x/GaP strained-layer superlattices (SLSs). This is the first demonstration of electrical activation of an implanted species with useful electrical characteristics in an SLS. X-ray diffraction indicates that the superlattice structure survived the implantation and annealing, and room temperature electrical measurements indicate diode ideality factors of ∼ 2.0 over seven decades of forward current for these devices. Diodes formed in SLSs with n-type background doping of 10¹⁷cm^-3exhibit room temperature reverse leakage currents of1.5\times10^{-7}A/cm²at -10V. The abrupt avalanche breakdown (at 100 µA) of these unpassivated devices occurs at -18V. The diodes show an uncoated peak external quantum efficiency of 30% for photons with energies slightly above the superlattice bandgap of 2.1eV.