Ultra-efficient RYGB SSL CRI = 90 CCT = 3,000K Δλ = 1 nm LER = 408 lm/W

Wavelength (nm) Relative Power Reflectance Factor nm 530 nm614 nm 573 nm (a) (b)

Wavelength (nm) Color Rendering Index Luminous Efficacy of Radiation (lm/W) (a)(b) 408 lm/W

Linewidth (nm) Wavelength (nm) Luminous Efficacy (lm/W) Wavelength (nm) Wavelength (nm) Wavelength (nm) RYGB RG B B RBGBBRBGBB lm/W 100% 90% 80% 70% 100% 90% 80% 70% 100% 90% 80% 70%

Schwarz 2007

As-grown thin AlGaInPepi Transparent substrate with chip shaping Red LEDs (AlGaInP) Blue LEDs (InGaN) Poor light extraction Advanced light extraction GaAs GaP C ext ~ 4% C ext ~ 61% C ext ~ 30% C ext ~ 80% AlGaInP Al 2 O 3 n - GaN p - Top-emitting LED Thin-film flip-chip LED with texturing n - GaN p- n - surface texture reflective n-contact reflective p-contact transparent p-contact transparent GaPlayers Absorbing GaAs substrate As-grown thin AlGaInPepi Transparent substrate with chip shaping Red LEDs (AlGaInP) Blue LEDs (InGaN) Early designs with inefficient light extraction Advanced designs with efficient light extraction GaAs GaP C ext ~ 4% C ext ~ 61% C ext ~ 30% C ext ~ 80% AlGaInP Al 2 O 3 n - GaN p - Al 2 O 3 n - GaN p - Top-emitting LED Thin-film flip-chip LED with texturing n - GaN p- n - surface texture reflective n-contact reflective p-contact transparent p-contact transparent GaPlayers Absorbing GaAs substrate

Year Extraction Efficiency (%) Thin AS Thick AS Thick AS + DBR Thick TS Improved TS Shaped TS Thick RS CC FC(Al) CC(PS) FC(Ag) VTF CC(PS/ITO) high power CC(PS/ITO) low power TFFC Evolution of Light Extraction in Visible LEDs