Integrated dual-color InGaN light-emitting diode array through transfer printing

Abstract

We demonstrate an integrated dual-color InGaN light-emitting diode (LED) array by transfer printing blue LED structures from their silicon growth substrate in between the pixels of a pre-processed green LED array on a sapphire substrate

Dual-Color Micro-LED Transmitter for Visible Light Communication

“…An important additional step is the deep etching of the mesa structure (90x90 µm 2 ) down to the patterned sapphire substrate (PSS). This allows to reduce the green micro-LED capacitance [2] as well as to compensate for height differences between the green and blue micro-LED in further processes [4].…”

Ultra-Low Cost High-Density Two-Dimensional Visible-Light Optical Interconnects

“…Processes to either thin down to the required thickness [45,46] or completely remove [47,48] the sapphire substrate have been demonstrated. Alternatively, the use of advanced assembly methods such as transfer printing [16,49], can enable the placement of the µLEDs directly onto the waveguide facets producing an effective "zero" distance between the waveguide input and µLED source. Such assembly methods can additionally allow the formation of multi-colour µLED arrays [49] which can reduce the optical crosstalk in such systems through the use of µLEDs with different emission wavelengths for adjacent waveguides.…”

“…Alternatively, the use of advanced assembly methods such as transfer printing [16,49], can enable the placement of the µLEDs directly onto the waveguide facets producing an effective "zero" distance between the waveguide input and µLED source. Such assembly methods can additionally allow the formation of multi-colour µLED arrays [49] which can reduce the optical crosstalk in such systems through the use of µLEDs with different emission wavelengths for adjacent waveguides. -blocking apertures: using an array of matching blocking apertures on the substrate underside can reduce the divergence of the µLED output beam and yield significant crosstalk suppression [ Fig.…”