In x Ga 1−x N light emitting diodes on Si substrates fabricated by Pd–In metal bonding and laser lift-off

Indium–gallium nitride $({\mathrm{In}}_x{\mathrm{Ga}}_{\text{1−x}}\mathrm{N})$ single-quantum-well (SQW) light emitting diodes (LEDs), grown by metalorganic chemical vapor deposition on sapphire, were transferred onto Si substrates. The thin-film ${\mathrm{In}}_x{\mathrm{Ga}}_{\text{1−x}}\mathrm{N}$ SQW LED structures were first bonded onto a $n^{+}-\mathrm{Si}$ substrate using a transient-liquid-phase Pd–In wafer-bonding process followed by a laser lift-off technique to remove the sapphire growth substrate. Individual, $\text{250×250\hspace{0.05em}μ}{\mathrm{m}}^{\mathrm{2}},$ LEDs with a backside contact through the $n^{+}-\mathrm{Si}$ substrate were then fabricated. The LEDs had a typical turn-on voltage of 2.5 V and a forward current of 100 mA at 5.4 V. The room-temperature emission peak for the ${\mathrm{In}}_x{\mathrm{Ga}}_{\text{1−x}}\mathrm{N}$ SQW LEDs was centered at 455 nm with a full width at half maximum of 19 nm.