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A novel 2-positional linked carbazole based β-diketone with methoxyl in the 7-position (EMOCTFBD), and its europium(iii) ternary complex Eu(EMOCTFBD)3phen were synthesized viaa dexterously designed indirect routine, where EMOCTFBD was 1-(9-ethyl-7-methoxyl-9H-carbazol-2-yl)-4,4,4-trifluorobutane-1,3-dione and phen was 1,10-phenanthroline. Eu(EMOCTFBD)3phen shows high thermal stability. The introduction of a methoxyl in the 7-position of the carbazole ring remarkably enhanced the excitation band intensity in the blue region, and the complex exhibited intense red emission under blue-light excitation. The lowest triplet state energy was measured and suggests the photoluminescence process as a ligand-sensitized luminescence process (antenna effect). A bright red-emitting diode was fabricated by coating the complex phosphor onto a ∼460 nm-emitting InGaN chip. All the results indicate that Eu(EMOCTFBD)3phen is an interesting red-emitting material excited by blue light, and therefore may be applied in many fields without UV radiation. [ABSTRACT FROM AUTHOR]

An efficient 2-linked carbazolyl β-diketonate europium(III) complex Eu(ETFMCTFBD)3phen was designed and synthesized, where ETFMCTFBD was 1-(9-ethyl-7-(trifluoromethyl)-9H-carbazol-2-yl)-4,4,4-trifluorobutane-1,3-dione and phen was 1,10-phenanthroline. Eu(ETFMCTFBD)3phen exhibits high thermal stability and excellent photoluminescence properties. The CIE chromaticity coordinates ( x=0.668, y=0.331) are close to the National Television Standard Committee (NTSC) standard values for red. The lowest triplet energy was measured and suggests the photoluminescence process as a ligand-sensitized luminescence process (antenna effect). A bright red light-emitting diode was fabricated by coating the complex phosphor onto a ∼395 nm-emitting InGaN chip. All the results indicate that Eu(ETFMCTFBD)3phen is a good candidate as a red component in the fabrication of white LEDs with a high color-rendering index. [ABSTRACT FROM AUTHOR]

Erbium ions and ytterbium ions (1021/cm3) were electrochemically codoped into porous silicon. When compared with the Er-doped porous silicon we found two salient features in its photoluminescence. One is that the 1.54 μm emission of Er3+ ions was 50 times stronger under 980 nm laser excitation at room temperature. This is due to the high efficiency of the Yb3+→Er3+ energy transfer. The other is that the photoluminescence intensity increases rapidly with temperature, while that in Er-doped porous silicon decreases monotonically with temperature. Our results show that the codoped Er/Yb porous silicon has a promising potential for the application in optical communications. [ABSTRACT FROM AUTHOR]