Randomly packed n -SnO₂ nanorods/ p-SiC heterojunction light-emitting diodes

A layer of randomly packed n SnO₂ nanorods is grown by vapor transport method on the p-SiC (4H) substrate to realize heterojunction light-emitting diodes. Diodelike rectifying current-voltage characteristics, with a turn-on voltage of ∼4.5 V and reverse leakage current density of <0.25 A/ m², are obtained at room temperature. Furthermore, electroluminescent spectra with emission peaks at around 395, 434, and 497 nm are observed from the heterojunction under forward bias. This is due to the relaxation of electrons in the conduction band of SnO₂ to the surface defect states and subsequent radiative recombination with holes injected from the p-SiC substrate.