Lattice Compression from Conduction Electrons in Heavily Doped Si:As

High-resolution x-ray scattering measurements on heavily doped Si:As (5×${10}^{21}$ As ${\mathrm{cm}}^{-3\mathrm{}}$) show lattice compression relative to pure silicon, $\frac{\Delta a}{a}=-0.0019\mathrm{}\pm 0.0003$, although extended x-ray-absorption fine-structure measurements show that the As-Si bond length is 0.06±0.02 Å greater than the usual Si-Si bond length. The overall lattice compression is attributed to increased population of conduction-band states which reduces Si-Si bond lengths. These measurements provide the first direct measurement of the hydrostatic deformation potential for the conduction-band edge in silicon, +3.3±0.7 eV.