Optical transitions in GaNAs quantum wells with variable nitrogen content embedded in AlGaAs

In situ determination of nitrogen content in InGaAsN quantum wells

Optical transitions in piezoelectrically polarized GaInNÕGaN quantum wells

The electronic band structure in polarized GaInN/GaN heterostructures is studied in photoluminescence excitation spectroscopy. Within multiple quantum well samples optimized for homogeneity, sets of narrow excitation maxima with full width at half maximum values of 10 and 25 meV (T'12 K! are identified and attributed to interband transitions involving excited quantized states of the quantum wel...

Room temperature spin diffusion in (110) GaAs/AlGaAs quantum wells

Transient spin grating experiments are used to investigate the electron spin diffusion in intrinsic (110) GaAs/AlGaAs multiple quantum well at room temperature. The measured spin diffusion length of optically excited electrons is about 4 μm at low spin density. Increasing the carrier density yields both a decrease of the spin relaxation time and the spin diffusion coefficient Ds.

Selective exciton formation in thin GaAs-AlGaAs quantum wells

We have found experimentally, that the exciton luminescence rise times in GaAdAlGaAs quantum wells oscillate as a function of incident laser energies. Guided by MonkCarlo simulations we interpret these results as the occurrence of selective LO-phonon assisted exciton formation. In the photoexcitation of semiconductors excitons can be generated either directly with high momentum or by free elect...

Excitons in undoped AlGaAs/GaAs wide parabolic quantum wells

In this work the electronic structure of undoped AlGaAs/GaAs wide parabolic quantum wells (PQWs) with different well widths (1000 Å and 3000 Å) were investigated by means of photoluminescence (PL) measurements. Due to the particular potential shape, the sample structure confines photocreated carriers with almost three-dimensional characteristics. Our data show that depending on the well width t...