Light emission from Al/HfO_(2)/silicon diodes

摘要

The metal-insulator-silicon light-emitting diode (MIS LED) using a high-dielectric-constant material (HfO_(2)) is studied. The external quantum efficiency for light emission at room temperature from the MIS LED was observed to be 2.0×10~(-6), as compared to 0.5×10~(-6) for the metal-oxide-silicon (MOS) LED. The large hole concentration at the Si/HfO_(2) interface created by the high dielectric constant of HfO_(2) may be responsible for the enhancement. The emission line shape of the MIS LED can be fitted by the electron-hole plasma recombination model, similar to the MOS LED. The Al/HfO_(2)/silicon LED with a high interface trap density has a continuous spectrum below the Si gap beside the electron-hole plasma emission, probably due to the radiative recombination between the electrons and holes via the interface states.