Isotopic effects on phonons and excitons in diamond studied by deep-ultraviolet continuous-wave photoluminescence spectroscopy

Abstract Photoluminescence (PL) spectroscopy is performed for natural-abundance ( N.A. C) and isotopically purified ( 13 C) synthetic diamond using a deep-ultraviolet continuous-wave laser. Because the excitation source creates low-density low-temperature excitons even under a moderate excitation power, the PL spectra show suppressed collisional and thermal broadening with a high signal-to-noise ratio. Our approach can accurately resolve the isotopic effects. The experimentally determined effects for phonons and excitons in diamond are Δ E TA = −2.5 meV, Δ E TO = −4.9 meV, Δ E LO = −5.7 meV, and Δ E ex = 14.5 meV.