Anthony L. Lipman

A new oxide/oxysulfide based phosphor triad and high-efficiency green-emitting (Y,Gd)2O2S:Tb phosphor for FED applications

An oxide/oxysulfide based phosphor triad with particle sizes of around 1micrometer (green Y2SiO5:Tb or Y2O2S:Tb, and blue Y2SiO5:Ce) down to 250nm for the red Y2O3: Eu is reported. These phosphors perform well in brightness under the conditions necessary for use in FEDs and are of suitable size for use in high definition screens. We also report a green emitting Y2O2S:Tb phosphor that has been prepared by a new method involving homogeneous precipitation of the precursors and a new firing regime. The resulting cathodoluminescent phosphor having submicrometer size particles has a luminous efficiency of 34.6 lm/W at an electron beam accelerating voltage of 5000 V.

Experimental and theoretical luminous efficacies of phosphors used in combination with blue-emitting LEDs for lighting and backlighting

— Phosphors that absorb blue light and emit in the green, yellow, and red have been synthesized, and their experimental and theoretical luminous efficacies are compared. It is proposed that a blue-emitting LED in combination with red-emitting Sr2Si5N8: Eu2+ and green-emitting SrGa2S4: Eu2+ phosphors is used as an energy-efficient white-light source for display backlighting applications.

Development of printable phosphor inks for high definition displays

Phosphors having sub-micrometer primary particle sizes and narrow size distributions were synthesized. They were then incorporated into screen printable, aqueous ink formulations. Aggregation and settlement problems in the inks were addressed and the rheological properties of the inks were adjusted in order to facilitate the printing of phosphors in high resolution features. The relative cathodoluminescence of adjacent pixels, all containing the same red emitting cubic-Y2O3: Eu3+ phosphor powder have been compared to assess the repeatability of the screen-printing of the inks.

P-84: Experimental and Theoretical Luminous Efficacies of Phosphors used for Producing White Light from Blue-emitting LEDs

Phosphors that absorb blue light and emit in the yellow, green and red have been synthesized, and their experimental and theoretical luminous efficacies are compared. These comparisons show that the formulation and preparation method of the phosphor are critical for producing energy efficient white LEDs for display and lighting applications.

P‐122: High Density Packing of Submicrometer Spherical Particles of the Y2O3: Eu3+ Phosphor for Low Voltage FPDs

Spherical, sub-micrometer Y2O3: Eu3+ phosphor particles have been synthesized by a homogenous solution method. These cubic Y2O3: Eu spherical phosphor particles (ca. 300 nm) will be ideal for FED devices as they can densely close-pack in very small pixels on screens (as shown herein.). The pixels are approximately hexagonal in shape where the length of the hexagonal side is about 5μm. The particles manifest high luminous efficiency (better than a commercial sample) under low voltage electron beam excitation. It is also shown herein that these particles are useful in voltage ranges up to 5000 V and perform well at such voltages.

42.4: A New Synthetic Route to ZnGa2O4:Mn2+ Phosphor Utilizing Oxalic Acid for Both Facile Synthesis and in Aiding to Ensure that Mn2+ is not Oxidized During the Firing Process

A low voltage cathodoluminescent ZnGa2O4:Mn2+ phosphor has been prepared by a novel oxalate gel synthetic route. This phosphor has a higher brightness than ZnGa2O4:Mn2+ phosphors made by solid state reactions and its smaller, more regular particles can pack densely in high definition screens. This means that the new method has the potential not only to produce superior Zn1−xMn xGa2O4 phosphor, but because of the relatively low firing temperature (500 °C) it should in addition be a cheaper process.