Carrier saturation in tin-doped InP films grown by liquid phase epitaxy.

We have investigated tin doping at high concentrations in InP films grown on 100>InP by liquid phase epitaxy. Contrary to previously published work, our Hall measurements show that the carrier concentration saturates at ~6x10(18)/cm(3) for a mole fraction of tin in liquid >~0.08. Measurements of actual tin concentrations in the solid by secondary ion mass spectroscopy indicate that a solid solubility limit is reached. Transmission electron microscopy reveals no precipitate formation.