Minority-carrier diffusion lengths in GaP/GaAsxP1−x strained-layer superlattices

Abstract

We have made the first measurements of the minority‐carrier diffusion lengths L_∥ and L_⊥ respectively in both n‐ and p‐ type GaP/GaAs_xP_1−x 〈100〉 strained‐layer superlattices (SLS’s) in directions parallel and perpendicular to the interfaces. Using room‐temperature optical techniques, we find that L_⊥≊0.1 μm, which is more than an order of magnitude smaller than L_∥≊1.5 μm. The latter is comparable to that measured in the bulk materials which comprise the SLS layers, while the former demonstrates the existence of large potential barriers in both the conduction and valence bands.