Alternating-current white thin-film light-emitting diodes based on hydrogenated amorphous carbon layer

Alternating-current white thin-film light-emitting diodes (ACW-TFLEDs) have been fabricated and demonstrated with composition-graded hydrogenated intrinsic amorphous silicon carbide (i-a-SiC : H) layers. It was found that H-2-plasma treatment of luminescent i-a-C:H layer played an important role in decreasing the ACW-TFLED electroluminescence (EL) threshold voltage, increasing the brightness, and broadening the EL spectrum. The EL spectra of the ACW-TFLED under either dc forward or reverse bias, or the sinusoidal alternating-current voltage were qualitatively very similar, with a peak wavelength at about 505 nm and a broad full-width at half maximum (FWHM) about 240 nm. This device revealed a brightness about 800 (500) cd/m(2) under dc forward (reverse) bias at an injection current density of 600 mA/cm(2).