Hydrogenated amorphous silicon carbide (a-SiC:H) p-i-n thin-film light-emitting diodes (TFLED's) with graded p+-i and i-n+ junctions have been proposed and fabricated successfully on an indium-tin-oxide (ITO)-coated glass. An obtained orange TFLED reveals a brightness of 207 cd/m2 at an injection current density of 600 mA/cm2, which is the brightest one ever reported for a-SiC:H TFLED's at the same injection current density. This significant increase of brightness could be ascribed to the combined effect of reduced interface states by using the graded-gap junctions, lower contact resistance due to post-metallization annealing, and higher optical gaps of the doped layers.
