Visible Light a-SiC Thin Film LED and its Application to New OE-Functional Elements

A visible-light injection-type electroluminescence thin film diode made of amorphous silicon carbide (a-SiC TFLED) has been developed. The device has a basic structure of p (a-SiC)/i (a-SiC)/n (a-SiC). The emission color could be controlled from red to green by adjusting the carbon content x in the a-Si1-x Cx luminescent i-layer. The brightness of 5 cd/m² was obtained for the yellow LED with a forward injection current density of 200 mA/cm². A series of technical data on the device fabrication technology, injection efficiency improvement and resulting device characteristics are presented, and discussed in relation to the carrier injection and recombination mechanisms. The developed a-SiC LED has some significant advantages over the conventional crystal LEDs, such as wide area, ease of fabricating integrated type multi-color or tunable color LEDs, and low cost. Utilizing these unique significances, new type of opto-electronic functional elements are proposed and discussed.