Abstract:
Organic light emitting devices are described wherein the emissive layer comprises a host material containing a fluorescent or phosphorescent emissive molecule, which molecule is adapted to luminesce when a voltage is applied across the heterostructure, wherein an intersystem crossing molecule of optical absorption spectrum matched to the emission spectrum of the emissive molecule enhances emission efficiency.
Abstract:
An organic light emitting device (OLED) which emits high intensity light is formed as a stack of individual OLEDs simultaneously emitting light of the same color.
Abstract:
Optical cavities in a stacked organic light emitting device (SOLEDs) can shift or attenuate the light emitted by the individual organic light emitting devices (OLEDs) in the stack. Interference caused by reflections within the stack, absorption, positioning of the light source, and the polarization of the emitted light can all determine how the spectra of the emitted light are affected by the SOLED structure. A detailed model that provides a good fit to measured SOLED emissions can be used to predict how a SOLED will affect light emitted by OLEDs. As a result, SOLED geometries that will optimize color saturation and external quantum efficiency can be predicted.
Abstract:
Light emitting devices including at least one pixel comprising a first light emitting stack and a second light emitting stack placed side-by-side. The first and second light emitting stacks each comprise a first OLED and a second OLED over the first OLED. The first light emitting stack further includes a downconversion layer under the first OLED. Together, the first and second stacks are capable of emitting any visible color of light.
Abstract:
Certain crystalline organic semiconductor compounds, such as 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA), when deposited by an ultrahigh vacuum process of organic molecular beam deposition, form highly ordered "quasi-epitaxial" films (32). Due to asymmetries in the molecular crystal structure of such compounds, the ordering of the films results in giant asymmetries in their dielectric properties. Such large dielectric asymmetries permit the construction of a variety of devices, including optical isolators (38), optically isolated lasers (48), optical isolated optical amplifiers (64), polarization-selective photodiodes (76), and metal-organic-inorganic semiconductor-metal detectors, among others.
Abstract:
An InGaAs photodiode is described in which a double layer of silicon nitride on the front surface serves several functions; both layers passivate the surface; an opening in the lower layer provides a diffusion mask for forming the p-n junction; and a narrower opening in the upper silicon nitride layer provides a deposition mask for forming a restricted area contact. In order to reduce strain near the junction, and hence reduce leakage currents and enhance reliability, the contact geometry has a narrow pedestal portion which contacts the surface in a zone remote from the junction edges and has a wider cap portion which is formed on the pedestal portion to seal the surface from the introduction of contaminants. The photodiode may be back-illuminated or front-illuminated.
Abstract:
An optoelectronic crossbar switch 50 for selectively connecting signals on a plurality of optical fiber channels 52 to a given number of output receivers 30-36. Each optical fiber channel is split into a different number of optical fibers 56(a-h) which are arranged into an array having a plurality of rows and columns. Each row contains a fiber from each channel. A current summation network 58 is provided for each row and advantageously employs a plurality of selectively activatable detectors 60-74. The detectors are held in their open circuit state via a CMOS multiplexer 80 so as to minimize crosstalk between addressed and nonaddressed detectors. The switch 50 construction also minimizes the number of required components.
Abstract:
A back-illuminated InGaAs photodiode is described in which a double layer of silicon nitride on the front surface serves several functions; both layers passivate the surface; an opening in the lower layer provides a diffusion mask for forming the p-n junction; and a narrower opening in the upper silicon nitride layer provides a deposition mask for forming a restricted area contact. In order to reduce strain near the junction, and hence reduce leakage currents and enhance reliability, the contact geometry has a narrow pedestal portion which contacts the surface in a zone remote from the junction edges and has a wider cap portion which is formed on the pedestal portion to seal the surface from the introduction of contaminants.
Abstract:
An integrated photodetector-amplifier is described which is planar and exhibits excellent circuit characteristics including low input capacitance, high speed, and high sensitivity. Also, certain self-alignment features and a planar technology made fabrication of the circuits simpler and easier than most such circuits.
Abstract:
The use of an organic material having a conjugated ring system such as 3,4,9,10-perylenetetracarboxylic dianhydride interfaced with a semiconductor material such as silicon yields quite acceptable rectifying properties. These properties are used to test the suitability of the substrate during processing. Additionally, these materials upon irradiation change refractive index, allowing production of optical devices such as gratings. The combination of electrical and optical devices formed using these organic materials also allows relatively simple fabrication of integrated opto-electronic structures.