Evidence of Type-II Band Alignment in III-nitride Semiconductors: Experimental and theoretical investigation for In(0.17)Al(0.83)N/GaN heterostructures

Type-II band alignment structure is coveted in the design of photovoltaic devices and detectors, since it is beneficial for the transport of photogenerated carriers. Regrettably, for group-III-nitride wide bandgap semiconductors, all existing devices are limited to type-I heterostructures, owing to the unavailable of type-II ones. This seriously restricts the designing flexibility for optoelectronic devices and consequently the relevant performance of this material system. Here we show a brandnew type-II band alignment of the lattice-matched In(0.17)Al(0.83)N/GaN heterostructure from the perspective of both experimental observations and first-principle theoretical calculations. The band discontinuity is dominated by the conduction band offset ΔE(C), with a small contribution from the valence band offset ΔE(V) which equals 0.1 eV (with [Image: see text] being above[Image: see text]). Our work may open up new prospects to realize high-performance III-Nitrides optoelectronic devices based on type-II energy band engineering.