Electrically driven on-chip transferrable micro-LEDs

Abstract

In this study, we report the experimental demonstration of electrically driven on-chip transferrable microdisk light-emitting diodes (LEDs). A vertical p– i– n doped AlGaInP microdisk, including multi-quantum-well structures, is top-down-fabricated, on-chip micro-transferred, and converted into single micro-LEDs. Optically transparent and mechanically flexible multilayered graphene sheets are judiciously designed and introduced to the top and bottom surfaces of a single microdisk, thereby forming the top and bottom contacts. Using electroluminescence measurements, the fabricated micro-LEDs are characterized; they exhibit diode-like transport behaviors, spectroscopic light-out vs current ( L– I) characteristics, and polarization-resolved emission properties. We believe that the proposed all-graphene-contact approach offers a direct and easy current injection scheme and further helps electrify various on-chip transferrable microarchitectures.

On-Demand Waveguide-Integrated Microlaser-on-Silicon

“…The schematics in Figure 2c illustrate the key steps involved in the on-demand laseron-Si integration. We used a previously developed PDMS microtip-assisted transfer printing technique to pick up the fabricated single microdisk on the InP substrate ((i)), move it to a receiving Si device substrate ((ii)), and align-transfer it on a target Si-post ((iii)) [21,30,31]. A PDMS stamp with a 20 × 20 × 20 µm 3 cubical microtip was surface-treated under the UV radiation with an illumination power of 10.4 mW/cm for 60 s to control the adhesive energy [37].…”

“…The schematics in Figure 2c illustrate the key steps involved in the on-demand laser-on-Si integration. We used a previously developed PDMS microtip-assisted transfer printing technique to pick up the fabricated single microdisk on the InP substrate ((i)), move it to a receiving Si device substrate ((ii)), and align-transfer it on a target Si-post ((iii)) [21,30,31].…”

“…Thus, to use these approaches, one should initially bond a large volume of III-V dies in an extended area of the coupling region, which inevitably sacrifices the massive III-V materials, high integration density, and compactness [7,10,12]. In this regard, a recently emerging integration technique of micro transfer printing using a microstructured adhesive polymer stamp has drawn considerable attention, demonstrating its ability to mechanically manipulate micro-and nano-scale materials and structures in a highly precise and accurate manner [18][19][20][21][30][31][32][33]. For example, an edge-emitting III-V gain media was transfer-printed using a polymer microtip [17,18].…”

“…Moreover, as more miniaturized and complicated photonic circuits are pursued, it has become of great importance to achieve the on-demand addressability at target locations. In particular, integration without causing significant mechanical damage, optical losses, and/or performance degradation has become critical but remains a challenge [21,30,31].…”