ELECTROLUMINESCENCE OF A-SIC-H P-I-N THIN-FILM LIGHT-EMITTING-DIODES WITH QUANTUM-WELL-INJECTION STRUCTURES

In order to improve the electroluminescence (EL) characteristics of hy drogenated amorphous silicon carbide (a-SiC:H) p-i-n thin-film light-e mitting diodes (TFLEDs), the quantum-well-injection (QWI) structures h ave been incorporated into their intrinsic (i-) layer. Two types of TF LED were fabricated to study the effect of the incorporated QWI struct ures on their EL characteristics: the device I contains a step-gap QWI structure of barrier (15 angstrom)/well (45 angstrom)/barrier (15 ang strom) inserted at both the p-i and i-n interfaces, and the device Il has only one graded-gap QWI structure of barrier (10 angstrom)/well (1 0 angstrom)/barrier (10 angstrom) inserted at the p-i interface. The o btained brightness of device I was about 10 cd/m2 at an injection curr ent density of 1 A/cm2. The emission light of device I was yellow-like as detected by human eyes. Whereas, for device II, the brightness was about 256 cd/m2 at 800 mA/cm2 and an orange light emission was observ ed.