Optically functional surface composed of patterned graded-refractive-index coatings to enhance light-extraction of GaInN light-emitting diodes
Graded-refractive-index (GRIN) coatings, composed of multiple dielectric layers of TiO 2 and
SiO 2 are sputter-deposited on the nitrogen-face of thin-film GaInN/GaN light emitting diodes
(LEDs). The thickness and refractive index of each layer in the GRIN stack is designed to
minimize light trapping inside the LED caused by total internal reflection at the
semiconductor–air interface. Patterning the GRIN stack forms an optically functional surface,
which converts trapped modes of light into desirable extracted modes that have preferential …
SiO 2 are sputter-deposited on the nitrogen-face of thin-film GaInN/GaN light emitting diodes
(LEDs). The thickness and refractive index of each layer in the GRIN stack is designed to
minimize light trapping inside the LED caused by total internal reflection at the
semiconductor–air interface. Patterning the GRIN stack forms an optically functional surface,
which converts trapped modes of light into desirable extracted modes that have preferential …