Experimental doping dependence of the lattice parameter inn-type Ge: Identifying the correct theoretical framework by comparison with Si

Abstract

Doping a semiconductor induces a change in its lattice parameter. This change is caused not only by the different sizes of the impurity and host atoms, but also by the strain developed when the occupation of electronic energy bands is modified. While these ideas are conceptually simple, experimentalists and theorists alike have struggled for decades to separate the size and electronic effects. Following up on the most significant earlier developments, which focused on doped Si, the authors present data for $n$-type Ge doped with novel precursors and suggest that trends as a function of the donor species in both Ge and Si hold the key to resolving the doping dependence of the lattice parameter into its two fundamental physical components.