Impact of structural nonuniformity on the operation of AlGaInP lasers at high compressive strain

A set of single 10 nm Ga_xIn_1-xP/(Al _xGa_1-x)_0.52In_0.48P quantum well lasers with compressively strained active regions have been grown by low pressure metal-organic chemical vapor deposition with the intention of examining the physical mechanisms which inhibit successful laser operation at high strain. In this paper we show that strain induced structural non-uniformity similar to Stranski-Krastanov growth is the primary mechanism for both the partial relief of strain and an increase in the optical losses which combine to cause an increase in the threshold current density as the compressive strain increases from 1% to 2%. In this paper we present a detailed analysis of the characteristics of the laser devices and using photoluminescence, electron microscopy, and x-ray microanalysis we relate the laser performance to the structural features we observe at high levels of mismatch between the active region and the material surrounding it.