Patent ID: 8946741
Filing Date: 2015-02-03
Classification: H01L

Abstract:
1. A light emitting device comprising: a first semiconductor layer having doping of a first type; a second semiconductor layer having doping of a second type; a light emitting region interdisposed between the first and the second semiconductor layers, wherein light generated in the light emitting region is extracted from the device via an upper surface of the second semiconductor layer, the light generated has a dominant wavelength, and the light generated has an effective wavelength in the device, a first electrode disposed on the first semiconductor layer; a second electrode disposed on the second semiconductor layer; and a first plurality of evenly distributed light extracting elements defined on an upper surface of the second semiconductor layer, the light extracting elements being adapted to couple light out of the device and to modify the far field emission profile of the device; wherein each of the light extracting elements is an elongate indentation in the upper surface of the second semiconductor layer having length, width, and depth dimensions such that the length of each indentation is at least twice the width of the indentation, the length of each indentation is greater than the effective wavelength of the generated light in the device, and the depth of each indentation extends from the upper surface of the second semiconductor layer in an orthogonal direction thereto but does not extend into the light emitting region; each elongate indentation in the first plurality has its length dimension oriented at a detuning angle relative to an average direction of the first plurality of elongate indentations, the magnitude of the detuning angle being greater than or equal to 0 degrees and less than 45 degrees, such that at least two elongate indentations in the first plurality are not parallel with one another; and, each elongate indentation in the first plurality is spatially separated from neighboring elongate indentations in the first plurality such that none of the elongate indentations in the first plurality intersect one another, whereby each indentation in the first plurality perturbs light generated in the light emitting region independently of the neighboring elongate indentations in the first plurality.