The luminescence of GaAs/AlGaAs multiple-quantum-well structures with different well widths, containing A(+) centers, was studied to determine the dependence of the center binding energy on quantum-well width. It is shown that the binding energy of the A(+) centers increases markedly with decreasing well width, becoming ten times greater in 10-nm-wide wells than in the bulk material. The binding energy of A(+) centers was found to depend on their concentration . (C) 2003 MAIK "Nauka /Interperiodica".