  III-Nitride light emitting diodes (LEDs) are widely used in a range of high
efficiency lighting and display applications, which have enabled significant
energy savings in the last decade. Despite the wide application of GaN LEDs,
transport mechanisms across InGaN/GaN heterostructures in these devices are not
well-explained. Fixed polarization sheet charges at InGaN/GaN interfaces lead
to large interface dipole charges, which create large potential barriers to
overcome. One-dimensional models for transport across such heterostructures
predict turn-on voltages that are significantly higher than that found in real
devices. As a result, conventional models for transport cannot predict the
performance of new designs such as for longer wavelength LEDs, or for
multi-quantum well LEDs. In this work, we show that incorporating low and high
Indium compositions within quantum wells at the submicron scale can provide
accurate prediction of the characteristics of GaN/InGaN light emitting diodes.
