Photoluminescence study of nitrogen effects on confined states in GaAs1−xNxGaAs quantum wells I. Dhifallah, S. Aloulou, A. Bardaoui, J. C. Harmand and R. Chtourou Eur. Phys. J. Appl. Phys., 47 3 (2009) 30302 Published online: 12 June 2009 DOI: 10.1051/epjap/2009107