Improving the growth of electron-doped Pr2−xCexCuO4+δ thin films made by pulsed-laser deposition using excess CuO

We report on a major improvement in the growth of electron-doped cuprate thin films by pulsed-laser deposition (PLD). Using Cu-rich targets, we affect the stability of secondary phases relative to Pr2−xCexCuO4+δ (PCCO). The resulting new generation of PLD PCCO epitaxial thin films shows no trace of the parasitic phases and resistivity lower than the old generation of thin films and comparable to the best films made by molecular-beam epitaxy. The absence of the intercalated phases even after reduction suggests that Cu migration is not required to induce superconductivity in our defect-free films.