The Photoluminescence (PL) from III–V semiconductor quantum wells, including InxGa1−xN/GaN quantum wells (QWs), show, in the usual case a monotonic blue shift on annealing. There were striking experimental reports that the PL of InxGa1−xN/GaN QWs of 30 Å and 40 Å width undergo an inflection on annealing: i.e. the peak initially moves towards red then it moves to the blue. Through quantum mechanical models and computations we have explained the phenomena and have shown that the inflections can occur only in InxGa1−xN/GaN structures of the order of 15 Å. These structures must occur in the QWs during growth, in the form of quantum dots or narrow necks in the highly fluctuating width of the quantum wells. This has been further supported by experimental reports where 15 Å QWs were annealed. Since the piezoelectric effect is negligible in 15 Å QWs, the observation is attributed to the two contesting phenomena on annealing. The energies of the quantum levels decrease and the band gap increases. © 2016