The influence of internal mechanical stresses on the GaAs-light-emitting diodes

The influence of internal mechanical stresses on design and performance of GaAs-LEDs is for the first time in detail investigated. The LED-structures were grown by liquid phase epitaxy from the melts doped with impurities of Si or Si and Sn simultaneously. The bending of crystal planes, internal friction, distribution of dislocations, and microhardness in p-n-junction regions have been measured. The value of internal mechanical stresses changes depending on concentration of doping impurities. When the internal mechanical stresses reach their minimum the LEDs perform the maximum value of quantum efficiency and maximum time of failure. The double Si and Sn doping is more effective. A qualitative model of all observed phenomena is offered