Optical concentrators for light-emitting diodes

摘要

Abstract: The incorporation of non-imaging optical concentrations in uncooled mid-IR LEDs is described. Novel micromachining methods are used to produce optical concentrators in the growth substrate of epitaxial InSb/InAlSb heterostructures. Resultant large area LED arrays, displaying both positive and negative luminescence, are shown to have optical gains of 3.5 over conventional mesas made form the same material. The LED technology shown also relies on the micromachined substrate being transparent to 3-5 $mu@m radiation and to act as a low resistance common contact. The use of degenerate doping in InSb is described, resulting in a shift in the room-temperature transmission to the 3-5$mu@m atmospheric window and providing high electrical conductivities. !14