Compositions, devices, and methods for optimizing photosynthetically active radiation by utilizing a composition comprising a quantum confinement material having an emission spectra of between 300 nm and 545 nm, and a quantum confinement material having an emission spectra of between 545 nm and 750 nm where the composition may be embedded in and/or coated on one or more transparent surfaces.

A wavelength converter includes a first phosphor activated with Cr.sup.3+; and a second phosphor activated with at least one ion of Ce.sup.3+ or Eu.sup.2+. A fluorescence spectrum of a fluorescence emitted by the second phosphor has a peak where a fluorescence intensity shows a maximum value in a wavelength range of 500 nm or more to less than 580 nm. The wavelength converter emits a fluorescence having a light component over an entire range of 500 nm or more to less than 580 nm. The wavelength converter emits a light having a spectrum in which a ratio of a minimum light emission intensity to a maximum light emission intensity is 40% or less in a wavelength range of 550 nm or more to 700 nm or less.

The invention relates to europium or samarium-doped terbium molybdates, to a method for producing said compounds, and to the use of the claimed europium or samarium-doped terbium molybdates as conversion lumiophores. The invention also relates to a light-emitting device containing a claimed europium or samarium-doped terbium molybdate.

The present invention relates to a composite ceramic which comprises a conversion phosphor and a further material, characterized in that the further material has a negative coefficient of thermal expansion, and to a process for the preparation thereof. Furthermore, the present invention also relates to the use of the composite ceramic according to the invention as emission-converting material, preferably in a white light source, and to a light source, a lighting unit and a display device.

A process for ultrasensitive in vitro detection and/or quantification of a substance of interest in a sample is performed by detecting the luminescence emission by photoluminescent inorganic nanoparticles. The process includes (i) use of photoluminescent particles comprising a photoluminescent inorganic nanoparticle consisting of a crystalline matrix having at least 10.sup.3 rare-earth ions, and coupled to a targeting agent for the substance to be analyzed, under conditions conducive to their association with the sample substance to be analyzed; (ii) exciting the rare-earth ions of the particles by an illumination device having a power of at least 50 mW and an excitation intensity of at least 1 W/cm.sup.2; (iii) detecting the luminescence emission by the particles after single-photon absorption; and (iv) determining the presence and/or concentration of the substance by interpreting said luminescence measurement. This process can be used for in vitro diagnostic purposes and as an in vitro diagnostic kit.

Provided is a phosphor represented by general formula (1) below,
(Gd.sub.1-x-y,Ln.sub.y,M.sup.II.sub.x).sub.3M.sup.III.sub.2(Ga.sub.1-z,M.sup.IV.sub.z).sub.3O.sub.12:Cr.sup.3+(1) where, in the formula, Ln is one or more elements selected from La, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Yb, and Lu, M.sup.II is a divalent element, M.sup.III is a trivalent element, M.sup.IV is a tetravalent element, and x, y, and z satisfy 0<x<0.5, 0y<0.5, and 0<z<0.5.

An oxide fluorescent material comprises: at least one first element M.sup.1 selected from Li, Na, K, Rb, and Cs; at least one second element M.sup.2 selected from Mg, Ca, Sr, Ba, and Zn; at least one third element M.sup.3 selected from B, Al, Ga, In, and rare earth elements; at least one fourth element M.sup.4 selected from Si, Ti, Ge, Zr, Sn, Hf, and Pb; O; and Cr, wherein when the molar ratio of the at least one fourth element M.sup.4 in 1 mol of the composition is 5, the molar ratio of the at least one first element M.sup.1 is 0.7 or more and 1.3 or less, the molar ratio of the at least one second element M.sup.2 is 1.5 or more and 2.5 or less, the molar ratio of the at least one third element M.sup.3 is 0.7 or more and 1.3 or less, the molar ratio of oxygen is 12.9 or more and 15.1 or less, and the molar ratio of Cr is more than 0 and 0.2 or less, and wherein the oxide fluorescent material has a light emission peak wavelength in a range of 700 nm or more and 1,050 nm or less in a light emission spectrum of the oxide fluorescent material.

A first luminescent material having peak emission wavelengths in the range of 1600-1900 nm comprises a Cr.sup.3+ and Tm.sup.3+ co-doped garnet phosphor having the general formula (Gd.sub.3-u-yTm.sub.yRE.sub.u) [Ga.sub.2-a-b-d-eLu.sub.aCr.sub.bSc.sub.d Al.sub.e]{Ga.sub.3-cAl.sub.c}O.sub.12 with RE=La, Y, Yb, Nd, Ho, Er, Ce, Lu, Sc and 0u2, 0<y1.5, 0a1, 0<b0.3, 0c3, 0d0.5, 0e1.8. A second luminescent material having peak emission wavelengths in the range of 1400-1600 nm comprises a Cr.sup.3+ and Ni.sup.2+ co-doped garnet phosphor having the general formula (Gd.sub.3-uRE.sub.u) [Ga.sub.2-a-b-d-eNi.sub.aCr.sub.bL.sub.d Al.sub.e]{Ga.sub.3-cAl.sub.c}O.sub.12 with RE=La, Y, Yb, Nd, Ho, Er, Ce, Lu, Tm, Sc and L=Ti, Zr, Hf, Sn, Ge, Si and 0u2, 0<a0.1, 0<b0.3, 0<b3, 0c0.15, 0e2. A light source comprises the first and second luminescent materials and one or more semiconductor light emitting diodes arranged to excite luminescence from the luminescent materials to provide short wavelength infrared emission over the range 1300-2000 nm.