Resonant excitation of visible photoluminescence from an erbium-oxide overlayer on Si

A thin ${\mathrm{Er}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}$ layer grown on a Si surface by vapor doping of Er exhibits intense photoluminescence in the green and red regions excited by laser beams in the 800 nm and 450–490 nm ranges. These intense light emissions take place via resonant two or one step photoexcitations of the $\text{4f}$ levels in ${\mathrm{Er}}^{\mathrm{3+}}$ ions. Our sample fabrication procedure is integrated circuit compatible and produces ${\mathrm{Er}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}$ layers of excellent homogeneity and quality as demonstrated in the optical measurements.