Vertical transport in group III-nitride heterostructures and application in AlN/GaN resonant tunneling diodes

We present a systematic study of vertical transport in AlGaN/GaN heterostructures. The influence of barrier thickness and Al-concentration on the current across AlGaN barriers is investigated experimentally and compared to model calculations. The effect of polarization fields on the electronic properties of single- and double barrier heterostructures is discussed and experimental results are reviewed. AlN/GaN double barrier RTD structures are fabricated under optimized growth conditions. Experimental analysis of their electronic properties reveals indications for resonant tunneling in the low forward bias regime.