Highly efficient green phosphors SrSi2O2N2 : Eu2+, suitable for white light emitting diodes (LEDs), was synthesized by solid-state reaction and their photoluminescence properties were investigated. SrSi2O2N2 : Eu2+ phosphors can be effectively excited by ultraviolet (UV)–Vis light (300–460 nm) and yield green emission with a single, intense, broad band centred at around 540 nm. Concentration quenching occurs in the phosphors when the Eu2+ concentration exceeds 2 at%. The mechanism of concentration quenching is confirmed to be dipole–dipole interaction of Eu2+. With an increase in the Eu2+ concentration, the emission band of Eu2+ shifts to a longer wavelength due to the 5d-orbit hybridization of Eu2+ with the host crystal and the energy transfer between adjacent Eu2+ ions. All the results indicate that SrSi2O2N2 : Eu2+ is a promising green phosphor for UV or blue chip based white LEDs.

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Photonic integration in a micrometer-thick indium phosphide (InP) membrane on silicon (IMOS) offers intrinsic and high-performance optoelectronic functions together with high-index-contrast nanophotonic circuitries. Recently demonstrated devices have shown competitive performances, including high sidemode-suppression ratio (SMSR) lasers, ultrafast photodiodes, and significant improvement in critical dimensions. Applications of the IMOS devices and circuits in optical wireless, quantum photonics, and optical cross-connects have proven their performances and high potential.

A series of Ce3+ and Eu2+ co-doped SrSi2normalO2normalN2 phosphors, whose features qualify them for consideration in white-light UV or blue light-emitting diodes (LEDs), was synthesized via a high temperature solid-state reaction under a reductive atmosphere. The dependence of luminescence properties of the produced powders on the concentration of an activator (Eu2+) and a coactivator (Ce3+) was investigated. The experimentally recorded luminescence spectra and the calculations of the efficiency of energy transfer from Ce3+ to Eu2+ and the critical distance between Ce3+ and Eu2+ suggest a resonance-type energy-transfer mechanism from Ce3+ to Eu2+ due to dipole–dipole interactions.

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