GaN/InGaN Blue Light‐Emitting Diodes on Polycrystalline Molybdenum Metal Foils by Ion Beam‐Assisted Deposition

Abstract

Light‐emitting diode (LED) arrays fabricated on a polycrystalline metal substrate are demonstrated using a novel technique that enables the growth of epitaxial metal‐organic chemical vapor deposition (MOCVD) GaN layers on non‐single‐crystal substrates. Epitaxial GaN is deposited directly on metal foil using an intermediate ion beam‐assisted deposition (IBAD) aligned layer. For a single 170 μm‐diameter LED on the metal foil, electroluminescence (EL) spectrum shows a peak wavelength of ≈452 nm and a full width at half maximum (FWHM) of ≈24 nm. The current–voltage (I–V) characteristics show a turn‐on voltage of 3.7 V, a series resistance of 10 Ω. LEDs on metal show a relative external quantum efficiency (EQE) that is roughly 3× lower than that of similar LEDs fabricated on a sapphire substrate. InGaN LEDs on large‐area non‐single‐crystal substrates such as metal foils enable large‐area manufacturing, reducing production cost, and opening the door for new applications in lighting and displays.