
314 Gallium Nitride (GaN): Physics, Devices, and Technology
layer superlattices [89], and transparent conducting ZnO nanoelectrodes [90].
Although a higher output power was measured in all the aforementioned devices,
voltage drop across the TJ was high, and led to high losses in LEDs. In this work,
we demonstrate MBE-grown TJs on commercial LED wafers with the lowest voltage
drop across the TJ ever reported [59].
InGaN/GaN TJs were grown by MBE on top of a metal-organic chemical vapor
deposition (MOCVD)-grown blue LED (TJLED). In the case of the InGaN TJLED
sample, magnesium delta doping was carried out to partially compensate the positive
charge ...