Complex sentence: During rapid crystal growth from the melt, dopant concentrations can far exceed the thermodynamic solubility limit through a solute trapping phenomenon, which is relevant for achieving sufficiently high free carrier concentrations since these dopants tend to be deep donors with high ionization energies.
Split into simpler sentences: During rapid crystal growth from the melting, dopant concentrations can far exceed the thermodynamic solubility limit through a solute trapping phenomenon. This is necessary to achieve sufficiently high free carrier concentrations, since these dopants tend to be deep donors with high ionization energies.