Sapphire irradiation by phosphorus as an approach to improve its optical properties

Abstract

Ion beam-induced luminescence (IBIL) is a versatile technique used to elucidate the chemical bond’s nature and analyze the defects study and impurities present in the material. In this study, IBIL spectra of phosphorus-irradiated sapphire has been analyzed under 2 MeV proton beam as a function of ion dose ranging from 1 × 1014 to 10 × 1014 ions/cm2 at room temperature in the wavelength range of 200–1,000 nm. The IBIL spectrum shows three kinds of luminescence features. The bands centered at 419 nm as F center and 330 nm as F+ center are associated with oxygen vacancies. The third kind of luminescence feature located at 704 nm is related to chromium impurities present in the crystal. The luminescence spectrum of the phosphorus-irradiated sapphire has been correlated with the spectrum obtained from pristine sapphire. The finding indicates that the intensity of defects due to phosphorus irradiation is reduced. As the proton ion fluence increases, the F and F+ center luminescence intensity eventually varies; it turns out that in phosphorus-irradiated sapphire, single crystal defects were reduced and the optical quality was improved.