Influence of internal mechanical stresses on the characteristics of GaAs light-emitting diodes

A systematic investigation of the influence of internal mechanical stresses on the characteristics of gallium arsenide light-emitting diodes (LED's) is performed. The LED structures are grown by liquid-phase epitaxy from a confined volume of a melt based on a solution of GaAs in Ga. The melt is doped with silicon or with silicon and tin. It is shown that the magnitude and sign of the internal mechanical stresses in the epitaxial layer are determined by the impurity concentration in the melt. The LED's fabricated from epitaxial structures with the smallest internal mechanical stresses have the greatest quantum efficiency and the slowest rate of degradation of their parameters. A model of the reorganization of the defect structure of gallium arsenide, which describes the observed phenomena, is proposed. (C) 1998 American Institute of Physics. [S1063-7826(98)02011-0].