Enhanced Light Extraction in GaInN Light-Emitting Diode With Pyramid Reflector

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> GaInN light-emitting diodes (LEDs) that employ a reflector consisting of an array of three-dimensional (3-D) SiO<formula formulatype="inline"><tex>$_{2}$</tex> </formula> pyramids and a Ag layer are demonstrated to have enhanced light extraction compared with GaInN LEDs with planar Ag reflector. Ray tracing simulations reveal that the pyramid reflector provides 14.1% enhancement in extraction efficiency. Consistent with the simulation, it is experimentally demonstrated that GaInN LEDs with the pyramid reflector show 13.9% higher light output than LEDs with a planar Ag reflector. The enhancement is attributed to the appearance of an additional escape cone for light extraction enabled by the 3-D pyramid reflector. </para>