Расчет упругонапряженной гетероструктуры AlXGaYIn1–X–YAs/InP с квантовыми ямами для эффективных лазерных излучателей

The compositions of epitaxial layers forming quantum-well heterostructures AlxGayIn1-x-yAs / InP for laser diodes with the radiation wavelength of 1.55 μm are calculated. When carrying out the calculations, the problem was to provide the maximum height of the energy barriers for effective limitation of charge carriers in the quantum wells. Along with taking care of the effects of the dimensional quantization of the energy of free charge carriers in allowed zones, the effect of elastic stress in epitaxial layers on the displacement of the edges of the energy bands were taken into account in the calculation. It is shown that in order to solve the posed problems it is necessary to form heterostructures with elastic compression stress in a quantum well and elastic tensile stress in the barrier layers. As a result of the calculations the authors suggest a structure that includes a barrier layer of Al0.28Ga0.30In0.42As with a thickness of 110 A and a quantum well Al0.03Ga0.23In0.74As in a layer with a thickness of 55A (with the mismatch between the parameters of the crystal lattice and the InP substrate - 0.8% and + 1.4 %, respectively). According to the calculation results, the indicated thicknesses of epitaxial layers do not exceed the critical values that can lead to the formation of imperfect dislocations at heterointerfaces.