Efficient energy transfer from silicon oxycarbide matrix to Er ions via indirect excitation mechanisms

Efficient Er excitation was observed in Er-doped silicon oxycarbide with strong room-temperature photoluminescence of ∼1540 nm within a broad (460-600 nm) band. Er PL power dependence modeling yielded an effective Er excitation cross section of approximately four orders of magnitude higher than direct Er excitation. PL for undoped a-SiC_0.5O_1.0 extended from visible to near infrared (500-750 nm), with intensity decreasing with Er doping. Er photoluminescence excitation overlapped with the Urbach edge in a-SiC_0.5O_1.0:Er absorption spectrum. Energy transfer from electron-hole recombination at band edges or/and defect levels in a-SiC _0.5O_1.0:Er may provide an efficient excitation route for Er ions via electron excitation from ground state (⁴I_15/2) to 4f levels.