| III-nitride semiconductors have the potential for very powerful electrostatic field engineering through the manipulation of polarization charges. This work explores the use of polarization fields for use in tunnel junctions for wide bandgap semiconductors, in particular. These tunnel junctions allowed light emitting diodes with multiple active regions, multiple colors, and eliminated p-type contacts. In addition, since the tunnel junction is formed without space-charge from dopants, this type of tunnel junction enables a single or multiple active region bipolar light emitting diode without any p-type material. These five types of devices were created and the characteristics of each are presented here. The creation of an efficient tunnel junction in the III-nitrides opens multiple future device engineering avenues in both emitters and absorbers; in particular, a stacked Schottky solar cell is proposed to make an ultra-efficient photovoltaic. |
