Polycrystalline nitride semiconductor light-emitting diodes fabricated on quartz substrates

We demonstrate the feasibility of polycrystalline nitride semiconductor light-emitting diodes (LEDs). Here, polycrystalline LEDs were deposited on quartz substrates, incorporating a layer structure identical to that used for epitaxially grown LEDs. The deposition exhibits a tendency to produce c-oriented crystallites. Violet-blue (430 nm) operation of a polycrystalline LED is demonstrated, with spectral width of 38 nm, and emission efficiency approximately two orders of magnitude lower than for single-crystal LEDs. These LEDs could potentially be incorporated in large-area displays, since the deposition of polycrystalline materials avoids single-crystal substrates required for conventional nitride semiconductor light emitters.