Impact of two-floor air prism arrays as an embedded reflector for enhancing the output power of InGaN/GaN light emitting diodes

Hyung Gu Kim; Hyun Kyu Kim; Hee Yun Kim; Jae Hyoung Ryu; Ji Hye Kang; Nam Han; Uthirakumar, Periyayya; Chang-Hee Hong
November 2009
Applied Physics Letters;11/30/2009, Vol. 95 Issue 22, p221110
Academic Journal
This paper reports on the impact of two-floor air prism (TFAP) arrays InGaN/GaN light emitting diodes (LEDs) as an embedded reflector with low refractive indices. The reflectance spectra, measured over the entire visible spectral region, shows strong reflectance modulations due to the TFAP arrays in GaN. The light output powers of TFAP LEDs is seen to be 2.62 times higher than that of conventional LEDs, and 1.55 times higher than that of LEDs with one floor air prism arrays, respectively, at injection currents of 100 mA. This significant enhancement is attributable to a combined effect of effective shaping with 62° angled sidewalls and high refractive index difference between the embedded air prism and the GaN.


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