Influence of barrier thickness on luminescence lifetime of the two-dimensional electron gas in InAlN/GaN heterostructures

The two-dimensional electron gas (2DEG) luminescence properties of InAlN/GaN heterostructures are explored by means of photoluminescence (PL) and time-resolved PL (TRPL) spectroscopy. It is found that the thicker the barrier, the longer the luminescence lifetime. As the barrier becomes thick, the quantum confinement of the triangular quantum well increases. It is believed the space wave function overlap between the better confined electrons and spreaded holes is fewer in thicker barrier sample, which results in a longer 2DEG PL lifetime.