Photoluminescence studies of stacked InAs/InP quantum sticks

The optical properties of stacked InAs/InP quantum sticks (QSs) are investigated as a function of the spacer layer thickness. The stacked structures are grown by solid source molecular beam epitaxy and studied by photoluminescence (PL), polarized photoluminescence and photoluminescence excitation. Like for single QS plane structures, the stacked structures show PL spectra consisting of several peaks attributed to ground and excited states. The lowest full-width at half-maximum (FWHM=25 meV for the ground state) is measured for the intermediate 15 nm spacer layer thickness. High room temperature PL intensity is recorded. The results are promising for the use of such structures as active media in laser devices.