Abstract:
In the manufacture of double heterostructure laser diodes using liquid phase epitaxy a source crystal precedes the laser substrate crystal through the process to ensure saturation of the various melts from which epitaxial growth is obtained. The source crystal has hitherto been discarded. The source crystal, since it immediately precedes the substrate crystal, also experiences epitaxial growth of a heterostructure but with heterostructure layer thicknesses unsuited for laser diode fabrication. By suitable processing of the source crystal after it is formed with a heterostructure, light emitting diodes can be produced so contributing to a 50% reduction in materials cost.
Abstract:
A surface emitting light emitting diode (LED) has a reflecting element to redirect light emitted away from the light emitting region towards an exit window. The LED bottom contact is formed over the reflecting element and a current confining path is set up within the LED to funnel current between the top and bottom contacts around the reflecting element and through the light emitting region.