The effect of m-plane GaN substrate miscut on the growth of InGaN/GaN quantum wells (QWs) was investigated. It was found that the miscut toward [0 0 0 1] c(+)-axis resulted in an increase of In incorporation efficiency and in a green-shift of the QW emission, while the miscut toward [1 1 (2) under bar 0] a-axis resulted in even higher In compositions but it also led to an increased epitaxial surface roughness and deterioration of the QW structures. The results indicated that miscut toward a-axis is undesirable while miscut toward c(+)-axis is beneficial for achieving longer wavelength emission in QWs grown on m-plane GaN substrates. (C) 2010 Elsevier B.V. All rights reserved.