Tailoring the Hole Mobility in SnO Films by Modulating the Growth Thermodynamics and Kinetics

Abstract

Obtaining semiconducting properties that meet practical standards for p-type transparent oxide semiconductors is challenging due to the balance between the defects that generate hole and electron carriers. Here, we demonstrate that modulating the individual thermodynamic and kinetic conditions during the growth of p-type oxide SnO films is beneficial in tailoring their semiconducting properties. By tuning the growth temperature and laser fluence for pulsed laser deposition, the hole carrier density dramatically changes from approximately 4 × 1016 to 6 × 1018 cm–3 at room temperature. The room-temperature hole mobility (μ) strongly depends on the carrier density (n), and their relationship is like a “volcano-shaped” curve. This suggests the competition between several scattering sources, such as the ionized impurity scattering (μ ∝ n–1), and grain boundary and/or dislocation scattering (μ ∝ n0.5) for higher and lower n, respectively. The hole mobility is enhanced to approximately 21 cm2 V–1 s–1 at room temperature, which is the highest recorded for SnO films to date. These findings provide important guidelines for designing all-oxide transparent electronic devices.