Abstract: A spin-polarized electron generating device includes a substrate, a buffer layer, a strained superlattice layer formed on the buffer layer, and an intermediate layer formed of a crystal having a lattice constant greater than a lattice constant of a crystal of the buffer layer, the intermediate layer intervening between the substrate and the buffer layer. The buffer layer includes cracks formed in a direction perpendicular to the substrate by tensile strain.

Abstract: To provide implement a spin-polarized electron generating device having high spin polarization and high external quantum efficiency while allowing a certain degree of freedom in selecting materials of a substrate, a buffer layer, and a strained superlattice layer. In a spin-polarized electron generating device having a substrate, a buffer layer, and a strained superlattice layer formed on the buffer layer, an intermediate layer formed of a crystal having a lattice constant greater than that of a crystal used to form the buffer layer intervenes between the substrate and the buffer layer. With this arrangement, tensile strain causes cracks to be formed in the buffer layer in a direction perpendicular to the substrate, whereby the buffer layer has mosaic-like appearance. As a result, glide dislocations in an oblique direction do not propagate to the strained superlattice layer to be grown on the buffer layer, thereby improving crystallinity of the strained superlattice layer.