We describe the fabrication of B and P doped SiGeSn ternaries, lattice-matched to Ge, with compositions adjusted to independently tune the band gap. These are deposited at 320-350 °C with superior crystallinity and morphology via in situ reactions of diborane (p -type) and designer P (SiH 3) 3 and P (GeH3) 3 precursors (n -type). Device-level carrier concentrations in the 1019 - 1020 / cm3 range are produced yielding film resistivities and carrier mobilities comparable to those of Ge indicating negligible alloy scattering. High boron levels induce a significant and systematic contraction of the host lattice, which is compensated by an adjustment of the Sn/Si ratio in accord with a simple model based on Vegard's law, the mismatch of covalent radii of the constituents, and the absolute hydrostatic deformation potentials for the band edges.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)