LED with Upstanding Nanowire Structure and Method of Producing Such

Abstract

The present invention relates to light emitting diodes, LEDs. In particular the invention relates to a LED comprising a nanowire as an active component. The nanostructured LED according to the embodiments of the invention comprises a substrate and at an upstanding nanowire protruding from the substrate. A pn-junction giving an active region to produce light is present within the structure. The nanowire, or at least a part of the nanowire, forms a wave-guiding section directing at least a portion of the light produced in the active region in a direction given by the nanowire.

1 . A method of fabricating a nanostructured LED, comprising first growing a nanowire over a substrate in a first growth mode promoting nanowire growth followed by selectively, epitaxially growing a semiconductor volume element on an upper portion of the nanowire in a second growth mode promoting radial growth of the semiconductor volume element. 
     
     
         2 . The method of fabricating a nanostructured LED according to  claim 1 , comprising:
 forming a catalyst island on a substrate;   growing a nanowire from the catalyst island, the growth parameters being adjusted for catalytic nanowire growth;   depositing a mask material around the nanowire;   partially etching back the mask material to expose an upper part of the nanowire; and   selectively growing the volume element, the growth parameters being adjusted to provide radial growth.   
     
     
         3 . The method of fabricating a nanostructured LED according to  claim 2 , further comprising forming a stem on the nanowire by depositing a reflective layer or a selective growth mask covering a lower part of the nanowire, and radially growing a cladding layer or the nanowire to increase the nanowire thickness.