Abstract:
The use of highly compressively strained In1−xGaxAs quantum wells having a high In content for the detection of light to a wavelength of &lgr;≈2.1 &mgr;m is disclosed. Crystal quality is maintained through strain compensation using tensile strained barriers of InGaAs, InGaP, or InGaAsP. High efficiencies have been achieved in detectors fabricated using this technique. The theoretical cutoff wavelength limit for diodes fabricated using this technique is calculated to be &lgr;˜2.1 &mgr;m. Lattice mismatched layers may be used to transition between compressively strained layers and tensile strained layers to prevent the crystal from breaking up. Multiple quantum wells are formed with multiple periods of strained InGaAs, transition layers and tensile strained layers. These detectors have application in semiconductor, amplifiers, detectors, optical switches, images, etc.
Abstract:
A light emitting device including a pixel having a substantially transparent anode; a hole transporting layer over the anode; an emission layer over the hole transporting layer; a blocking layer over the emission layer; an electron transporting layer over the blocking layer; and a cathode in electrical contact with the electron transporting layer.
Abstract:
An organic light emitting device (OLED) having an inverted structure including a cathode layer which is deposited on a substrate and on top of which an electron transporting layer (ETL), an electroluminescent (EL) layer, a hole transporting layer (HTL), a protection layer and an anode are deposited in sequence. The inverted OLED (IOLED) provides improved longevity, flexibility and efficiency over conventional OLEDs.
Abstract:
The present invention concerns a multicolor display device, comprising a transparent substrate, fluorescent dye deposited in a dye layer onto the substrate by ink jet printing, and a source of radiation for illuminating said fluorescent dye. The present invention also concerns methods for creating such a device.
Abstract:
An organic luminescent coating such as Aluminum-Tris-Quinolate is applied to a light detector for converting UV to green light to improve the efficiency of the light detector. The coating also provides anti-reflection properties when of sufficient thickness.
Abstract:
Arrangements for biasing the individual light emitting elements of a stacked organic light emitting device (SOLED). A circuit is provided for independently driving the individual OLEDs in a conventional SOLED having one electrode coupled to ground potential and one further electrode for each of the OLEDs in the stack. Additionally, new SOLED structures are described in which each OLED in the stack is provided with a ground reference. A SOLED combining upright and inverted OLEDs is also described.
Abstract:
The present invention is directed to organic light emitting devices comprised of an electroluminescent layer containing a host material comprised of a metal complex of (5-hydroxy)quinoxaline: ##STR1## wherein M is Al, Ga, In, Zn or Mg, with n=3, if M is Al, Ga or In and n=2, if M is Zn or Mg, and to a method for fabricating such devices. Further disclosed for use in the electroluminescent layer of organic light emitting devices are dopant materials comprised of a bisphenyl-squarilium compound, an indigo dye compound or a fullerene compound.
Abstract:
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.
Abstract:
All-optical modulation occurs in crystalline organic semiconductor waveguides (10a) grown by the ultrahigh vacuum process of organic molecular-beam deposition onto substrates (10b). Two light beams with wavelengths of 1.06 and 0.514 .mu.m from a first source (12) and a second source (34), respectively, may be used as the guided and the pump light sources, respectively. A resonant non-linear coefficient at room temperature of 5.4.times.10.sup.-5 cm.sup.2 /W at 1.06 .mu.occurs at a pump intensity of 1.0 W/cm.sup.2. This large non-linear effect is attributed to free electron-hole pairs produced by the dissociation of excitons generated by the short wavelength beam. A carrier lifetime of (17.+-.1) us, which determines the modulator switching time, is in good agreement with theoretical predictions. This appears to be the first observation of free-carrier-induced index modulation in crystalline organic waveguides.
Abstract translation:全光调制发生在通过有机分子束沉积到基板(10b)上的超高真空工艺生长的结晶有机半导体波导(10a)中。 分别来自第一源(12)和第二源(34)的波长为1.06和0.514(my)m的两个光束可以分别用作被引导和泵浦光源。 在1.06(me)时,在室温为5.4×10 -5 cm 2 / W的共振非线性系数发生在1.0W / cm 2的泵浦强度下。 这种大的非线性效应归因于由短波长束产生的激子解离产生的自由电子 - 空穴对。 确定调制器切换时间的(17 + -1)us的载波寿命与理论预测非常一致。 这似乎是结晶有机波导中自由载体诱导的指数调制的第一次观察。
Abstract:
The disclosed invention as direction to a semiconductor material avalanche photodiode of a separate multiplication and absorption region heterostructure design (SAM-APD). The improved SAM-APD of this invention is characterized by a plurality of floating guard rings which are separated about a central region and doped in the opposite high concentration from that of the multiplication region in which they are positioned. These rings float in the sense that they have no contact with the metalized p-contact of the photodiode; and, therefore, no direct contact with the current source. This structure results in an enhanced avalanche effect in the central region with limited edge breakdown undesirable consequences. In addition to this structure, an alternative embodiment suggests the use of both a floating ring and this slab below the central region, of a dimension slightly smaller than the smaller region and concentric with it to achieve an optimized central avalanche breakdown with reduced edge breakdown of the electric fields formed during reversed biasing of the APD (avalanche photodiode).