An edge-emitting LED in which light produced in the active layer optically tunnels out of the active layer through a thin confining layer into a single guide layer which is composed of a material which does not absorb light energy. The guide and active layers are constructed so that they are surrounded by layers of lower index of refraction so that an optical wave guide is formed. To minimize light losses by absorption, the non-absorbing guide layer is preferably much thicker than the active and...

A high efficiency edge-emitting LED is disclosed in which optical radiation produced in an active layer of the device leaves the device without being substantially absorbed by the material comprising the active layer. The device is constructed so that an optical waveguide is formed such that light produced in the active layer either leaves the device without any reflections or with a maximum of one reflection. The thickness of the active layer and the compositions of the active layer and confini...

A surface-emitting, light emitting device has a columnar active region of one direct bandgap semiconductor and a surrounding confining region of a higher bandgap semiconductor. Contacts are made to the active and confining regions and a window is formed in the device in alignment with the active region to permit light emission from the device. The semiconductors are doped to establish a pn junction within a carrier diffusion length of the heterojunction between the active and confining regions, ...

Light emitting arrays in which the light source is positioned between two opposed reflector surfaces. The light from the source is reflected back past the source by a first reflector and then re-reflected by a second reflector back past the light source to the first reflector. A very thin assembly is obtained. The arrangement is particularly suitable for light emitting diodes and can be used for character displays.

A light-emitting diode array comprises a substrate of insulating material having one side formed with a plurality of steps. A separate row of spaced-apart, similarly oriented diodes is disposed on the tread surface of each of the steps. Corresponding diodes in the different rows are disposed in columns, and the diodes in each of the columns are connected in series. A method of making the light-emitting diode array comprises the operations of (a) forming a plurality of steps in one side of a subs...

A device for injecting electric charge into fluids consists of a p-n junction diode having the junctions so positioned that an active region of the semi-conductor is in contact with the fluid. A reverse electric field of a magnitude sufficient to release charge carriers having energies greater than the potential barrier at the surface of the semi-conductor is applied to the junction so that charge carriers are emitted from the active region. An electrode is also immersed in the fluid to enable a...

A surface-emitting light-emitting diode having increased light emission is provided. The surface-emitting light-emitting diode includes a substrate, a light generating layer comprising an active layer for generating light, and an upper clad layer and a lower clad layer formed on and below the active layer, respectively, a lower contact layer formed between the light generating layer and the substrate, a buffer layer formed between the lower contact layer and the substrate, a lower ohmic metal la...

A double heterostructure light emitting semiconductor device is described wherein a narrow bandgap active region is sandwiched between two wider bandgap cladding layers, one of which contains a p-n homojunction. The purpose is to separate the p-n junction from the active region and, thus, to have the active region bounded by two isotype (p-p or n-n) heterojunctions. This configuration significantly reduces nonradiative interface recombination current which occurs principally at the anisotype (p-...

Advantageous operation can be achieved in a semiconductor heterostructure light emitting device by utilizing a single thin active layer which exhibits quantum size effects. It has been found that performance can be degraded by employing a single quantum layer that is thinner than a certain minimum thickness, this minimum thickness being about 100 angstroms, (the approximate carrier scattering path length). In one form of the invention, there is provided a semiconductor heterostructure device whi...

A light-emitting semiconductor device is provided having a light-emitting semiconductor element emitting light in two directions. The light-emitting element is disposed in a housing so that one light-emitting face of the semiconductor element adjacent a heat sink, and a light guide is arranged to confront the other light-emitting face of the semiconductor element and to guide light from said other light-emitting face to the outside of the housing. In this device, the end face of the light guide ...