Аннотация:Numerical calculations of the valence band and conduction band size quantized levels in a strained p-AlxGa1-xAs/GaAs1-yPy/n-AlxGa1-xAs (y = 0.16) double heterostructure were performed for different values of the external uniaxial compression along [110] direction. They indicate that the two upper levels in the valence band merge at pressure about 4 kbar and a strong state mixing develops around the merging point. The results of calculations explain the nonlinear character of the photon energy shift and electroluminescence intensity increase that were experimentally observed in these structures under uniaxial compression up to 5 kbar.