Visible cathodoluminescence from Eu-implanted single- and polycrystal c-BN annealed under high-temperature, high-pressure conditions

摘要

Red and red/blue cathodoluminescence in the temperature range 12 to 300 K was obtained from single- and polycrystal cubic boron nitride bulk samples implanted with europium and annealed under high-temperature, high-pressure conditions. All observed radiative intra-4f electron transitions of Eu~(3+) can be assigned to transitions starting from the ~(5)D_(0) level of Eu~(3+). Additionally, radiative 4f~(N-1)5d→4f~(N) electron transitions related to Eu~(2+) were detected in the polycrystal c-BN specimens. The higher-resolution Stark level as well as the time-resolved cathodoluminescence spectroscopy suggest that the Eu ions occupy at least two different sites in the c-BN host.