Carrier injection mechanism in an a-SiC p-i-n junction thin-film LED

A systematic study has been done on the carrier injection mechanism and electroluminescent properties of an amorphous silicon-carbide p-i-n junction thin-film light-emitting diode (a-SiC TFLED). The analysis of the junction characteristics reveals that the main contribution to the junction current comes from electrons injected by tunneling from the n-layer through the i-n interface notch barrier, while the electroluminescent property of the TFLED is determined by the injection process of holes. This process also takes place by tunneling, in this case from the p-layer through the p-i interface notch barrier. On the basis of the results of the analysis, a method to improve the LED performance using a hot-carrier-tunneling injector structure is proposed. With this structure, the brightness of the TFLED is increased by more than one order of magnitude to about 20 cd/m², with an injection current density of 600 mA/cm²