The Positron – the antimatter of an electron – has been used as a probe to study defect properties for many years. Because positrons are naturally trapped in vacancies of normal materials, from the e+-e– annihilation photons, specific void information can be extracted of the target. Being non-destructive and quantitative, positron spectroscopy has unique advantages over traditional intrusive and microscopic techniques. In addition, by moderating the positrons, one can utilize low-energy positron beam to examine very thin films. The NC State Intense Positron Beam facility provides both bulk and beam positron spectroscopy capabilities that are suitable for bulk and thin film (as thin as 20nm) measurements.