Optimized fabrication of high-quality Nd0.8Sr0.2NiO2 superconducting films by pulsed laser deposition

•The discovery of superconductivity in the infinite-layer nickelates has motivated tremendous efforts for its’ significance toward the understanding of superconductivity. However, the synthesis of infinite-layer nickelates is instable and has become a holdback to experimental progress.•Previous reports have pointed out that the precursor perovskite Nd0.8Sr0.2NiO3 phase is an essential precondition to achieve the superconducting Nd0.8Sr0.2NiO2 thin films, while an impurity phase with the Ruddlesden-Popper (RP) structure which hinders the implementation of superconductivity is inevitable during the growth of the Nd0.8Sr0.2NiO3 phase.•Our study shows that the inevitable impurity phase with the Ruddlesden-Popper structure is strongly affected by the laser fluence during the growth of the precursor perovskite Nd0.8Sr0.2NiO3 phase. And we believe that our study can further promote the research of nickelate superconductivity in terms of experimentation.