Three-dimensional arrays of self-ordered quantum dots for laser applications

Abstract

Semiconductor heterostructures with quantum dots (QDs) are experimentally proved to exhibit properties expected for zero-dimensional systems, e.g. ultrasharp luminescence lines up to high temperatures, massively increased exciton oscillator strength per unit volume and temperature insensitivity of the radiative lifetime. When applied to the injection lasers these advantages help to increase strongly material gain, differential gain, to improve temperature stability of the threshold current and to suppress chirp. Threshold current densities as low as 60 A/cm 2 at 300 K are obtained. Formation of QDs with properties satisfying device requirements on QD size, shape, uniformity and density became possible by utilizing self-ordering phenomena on crystal surfaces.