A multicolor organic light emitting device employs vertically stacked layers of double heterostructure devices which are fabricated from organic compounds. The vertical stacked structure is formed on a glass base having a transparent coating of ITO or similar metal to provide a substrate. Deposited on the substrate is the vertical stacked arrangement of three double heterostructure devices, each fabricated from a suitable organic material. Stacking is implemented such that the double heterostructure with the longest wavelength is on the top of the stack. This constitutes the device emitting red light on the top with the device having the shortest wavelength, namely, the device emitting blue light, on the bottom of the stack. Located between the red and blue device structures is the green device structure. The devices are configured as stacked to provide a staircase profile whereby each device is separated from the other by a thin transparent conductive contact layer to enable light emanating from each of the devices to pass through the semitransparent contacts and through the lower device structures while further enabling each of the devices to receive a selective bias. The devices are substantially transparent when de-energized, making them useful for heads-up display applications.

Transparent contacts for organic devices

The light-radiating semiconductor component has a radiation-emitting semiconductor body and a luminescence conversion element. The semiconductor body emits radiation in the ultraviolet, blue and/or green spectral region and the luminescence conversion element converts a portion of the radiation into radiation of a longer wavelength. This makes it possible to produce light-emitting diodes which radiate polychromatic light, in particular white light, with only a single light-emitting semiconductor body. A particularly preferred luminescence conversion dye is YAG:Ce.

Light-radiating semiconductor component with a luminescence conversion element

Methods for fabricating light emitting diode (LED) chips comprising providing a plurality of LEDs typically on a substrate. Pedestals are deposited on the LEDs with each of the pedestals in electrical contact with one of the LEDs. A coating is formed over the LEDs with the coating burying at least some of the pedestals. The coating is then planarized to expose at least some of the buried pedestals while leaving at least some of said coating on said LEDs. The exposed pedestals can then be contacted such as by wire bonds. The present invention discloses similar methods used for fabricating LED chips having LEDs that are flip-chip bonded on a carrier substrate and for fabricating other semiconductor devices. LED chip wafers and LED chips are also disclosed that are fabricated using the disclosed methods.

Wafer level phosphor coating method and devices fabricated utilizing method

A handheld and battery-operated far-ultraviolet plane-emission device is demonstrated. The device has low current consumption and stable operation at an output power of 0.2 mW at 225 nm, and may be useful in photochemical and biotechnological applications such as photo catalysis, sterilization and the modification of chemical substances.

Far-ultraviolet plane-emission handheld device based on hexagonal boron nitride

In a lighting package, a printed circuit board supports at least one light emitting die. A light transmissive cover is disposed over the at least one light emitting die. A phosphor is disposed on or inside of the light transmissive dome-shaped cover. The phosphor outputs converted light responsive to irradiation by the at least one light emitting die. An encapsulant substantially fills an interior volume defined by the light-transmissive cover and the printed circuit board.

Light emitting diode component

This paper reports on the ZnCa{sub 2}O{sub 4} phosphor investigated for its application to vacuum fluorescent displays (VFDs) utilizing low-voltage cathodoluminescence. It is expected that this oxide phosphor does not cause damage to filaments in VFD's, while it is a serious problem for conventional sulfide phosphors. This phosphor shows blue luminescence with a spectral peak at with 470 nm and a chromaticity at X = 0.170 and Y = 0.130. A luminous efficiency of 0.7 lm/W has been obtained, when the VFD with this phosphor is operated at 30 V dc. The results of high-temperature operating life test have proven the excellent stability of VFDs utilizing this phosphor.

The ZnGa2 O 4 Phosphor for Low‐Voltage Blue Cathodoluminescence

A new red phosphor, SrTiO3:Pr3+, was developed for vacuum fluorescent displays (VFDs) and field emission displays (FEDs). It was discovered that the addition of Al is essential to achieve a high luminous efficiency of low-voltage cathodoluminescence and photoluminescence. The mechanism underlying the improvement of the luminous efficiency by the addition of Al is discussed. With the addition of 17 mol% Al, luminance of 800 cd/m2 was obtained at the anode voltage of 50 V. Powder X-ray diffraction and Auger analysis showed that the Al ions react with the Sr ions to form SrAl12O19.

https://iopscience.iop.org/article/10.1143/JJAP.38.6387/pdf

A New Red-Emitting Phosphor, SrTiO3:Pr3+, for Low-Voltage Electron Excitation.

A phosphor is prepared by depositing a compound semiconductor of Groups III-V in the form of fine particles or a thin film on a surface of a carrier particle by hetero-epitaxial growth. Thus, the phosphor increased in quality is obtained with satisfactory reproducibility.

Phosphor and method for producing same

— FEDs are one of the attractive flat-panel displays that realize high-quality motion images and low power consumption. FEDs are constructed by using three elemental technologies: micro- or nano-fabrication technology of emitters, opto-electronic semiconductor technology of anode patterns, and vacuum packaging technology. Each of the three elemental technologies is essential to realize FEDs. The present status of each three technologies, especially the improvement of Spindt-type field emitters, the trend of flat vacuum packages, and development of phosphors for FEDs is described in this paper.

Development of field-emission displays

A fluorescent composition capable of emitting light of various luminous colors under electron or ultraviolet excitation and a fluorescent luminous device having mounted such a fluorescent composition mounter therein. The fluorescent composition has a general formula of ZnO.Ga 2 O 3 and emits light of a luminous spectrum distributed at an ultraviolet or visible region. The fluorescent composition includes a matrix of ZnO.Ga 2 O 3 and Cd doped in the matrix. The fluorescent luminous device includes at least one ZnO.Ga 2 O 3 :Cd phosphor deposited on anode conductors and at least one luminous display section having an ultraviolet excitable visible light emitting phosphor deposited thereon within a region of radiation of ultraviolet rays emitted from the ZnO.Ga 2 O 3 :Cd phosphor.

Hitoshi Toki

Papers

The ZnGa2 O 4 Phosphor for Low‐Voltage Blue Cathodoluminescence

A New Red-Emitting Phosphor, SrTiO3:Pr3+, for Low-Voltage Electron Excitation.

Phosphor and method for producing same

Development of field-emission displays

Fluorescent composition and fluorescent luminous device