Color LEDs with integrated optical filtering elements
A red LED includes a semiconductor LED layer having an active InGaN layer with intrinsic emission spectrum having L Dom in a range of from 580 nm to 620 nm. A filter is positioned over the semiconductor LED layer to filter shorter wavelengths of the intrinsic emission spectrum and shift L Dom by between 5 nm to 20 nm to a longer wavelength.
1 . A red LED, comprising:
a semiconductor LED layer having an active InGaN layer with an emission spectrum having a peak wavelength in a range of from 580 nm to 620 nm; and
a filter positioned over the semiconductor LED layer, the filter including one or more of an absorptive material, a polycrystalline II-VI semiconductor alloy, at least one metallic material, or a wavelength selective mirror, and the filter configured to filter shorter wavelengths of the emission spectrum of the active InGaN layer and shift the peak wavelength by between 5 nm to 20 nm to a longer wavelength.
2 . The LED of claim 1 , further comprising a transparent conductive layer attached or a transparent sapphire layer disposed between the semiconductor LED layer and the filter.
3 . The LED of claim 1 , wherein the red LED is a microLED.
4 . The LED of claim 1 , wherein the red LED forms a part of an RGB display.
5 . The LED of claim 1 , wherein the polycrystalline II-VI semiconductor alloy comprises one or more of cadmium (Cd), selenium (Se), sulfur(S), zinc (Zn), or tellurium (Te).
6 . The LED of claim 1 , wherein the polycrystalline II-VI semiconductor alloy has a thickness in a range of from 200 nm to 2000 nm.
7 . The LED of claim 1 , wherein the at least one reflective metallic material comprises one or more of Au, Au—Cu alloys, TIN, HIN, ZrN, Ni, or CrN.
8 . The LED of claim 1 , wherein the wavelength selective mirror comprises one or more of SiN x , TiO 2 , SiO 2 , or aluminum indium nitride (AlInN), or aluminum indium gallium nitride (AlInGaN).