Authors: X. Wang, J.J. Cole and H.O. Jacobs
Affilation: University of Minnesota, United States
Pages: 526 - 529
Keywords: nanowire, ZnO, heterojunction, light emitting diode, device
ZnO nanowire/p-GaN heterojunction light emitting diodes (LEDs) were fabricated by growing ZnO nanowire vertical arrays in aqueous solution on Mg-doped p-GaN films. Diode-like, rectifying I-V characteristics were recorded at room temperature and a “current crowding” effect was observed due to the high sheet resistance of the GaN film. The majority of voltage drop was found to occur during current transport in the GaN film. Light emission centered at 390 nm and 585 nm was observed under forward bias while a broad emission centered at 520 nm was found under reverse bias. Two emission mechanisms have been explored: space charge limited current in the forward bias and tunneling in the reverse bias.