Oxygen vacancy effect on ultra-fast carrier dynamics of perovskite oxide La_(0.7)Sr_(0.3)MnO_3 thin films

摘要

Complex oxide thin films, such as La_(0.7)Sr_(0.3)MnO_3 (LSMO), are widely studied for a variety of applications. Transient reflectivity (TR) measurements on LSMO indicate enhanced surface recombination of charge carriers in films less than 20 nm in thickness. Oxygen growth pressure variation illustrates that higher oxygen pressures provide more electron dominance in the system, and producing a larger band filling effect which eventually results in higher excitations. Wavelet analysis can distinguish abrupt oscillatory modes with close energy ranges and have been introduced as a method to study sound velocities in ultra-thin films.