Laser doping of chromium in 6H-SiC for white light emitting diodes

Laser doping has been utilized for fabricating white light emitting diodes with 6H-SiC wafers. The emission of different colors to ultimately generate white light is tailored on the basis of donor acceptor pair (DAP) recombination mechanism for luminescence. Chromium (Cr), which is an unconventional dopant that produces multiple acceptor sites per atom, was incorporated into SiC and conventional dopants such as aluminum (Al) and nitrogen (N) were also laser-doped to produce acceptor and donors states, respectively. A p−n junction was fabricated with these dopants and an electroluminescent broad spectrum (400–850 nm) corresponding to white light was observed. This white light is a result of the combination of red, green, and blue lights formed due to DAP recombination between Al–N (blue, 460–498 nm), Cr–N (green, 521–575 nm) and additional other impurity state transitions (red, 698–738 nm).