The paper considers new opportunities for design of various optoelectronic devices opened by the use of polarization doping in III-nitride heterostructures, including distributed polarization doping (DPD) in graded-composition alloys. The polarization doping is routinely exploiting in high-electron mobility transistors for a long time. In contrast, this concept has not yet been applied to light-emitting diodes (LEDs), laser diodes (LDs), and solar cells (SCs) until recently, in spite of its great potential advantage – capability of producing holes with high concentrations that can never be achieved by conventional impurity doping. Using simulations, we apply the concept of polarization doping to find efficient ways for solution of practically important problems: (i) improvement of p-doping in deep-UV LED structures, (ii) development of p-type Ohmic contact to AlGaN alloys with high aluminum content, and (iii) development of III-nitride tunnel junctions (TJs) capable of forward bias operation.
Band diagram and distribution of carrier concentrations in the prototype of acceptor-free deep-UV LED structure considered in the paper.