Optical properties of delta-doped ZnSe : Te grown by molecular beam epitaxy: The role of tellurium - art. no. 155205

We have studied the optical properties of the delta -doped ZnSe:Te system u sing photoluminescence (PL) and x-ray and Raman scattering. Two different t ypes of sample were investigated, (1) with a single delta layer and (2) wit h three adjacent delta layers separated by undoped layers. All of these sam ples are of reasonable crystalline quality and have the symmetry of the hos t ZnSe lattice as determined by x-ray and Raman scattering. The PL from eac h sample is very similar to the PL from bulk Zn-Se-Te solutions at low Te c oncentrations. The PL from the single-delta -doped material shows emission relatively close to the band edge which we attribute partly to Te-2 cluster s (nearest-neighbor pairs) and partly to non-nearest pairs. This PL changes with storage time, from which we conclude that the nearest-neighbor pairs are more stable than non-nearest-neighbor pairs. The triple-delta -doped ma terial also shows a deeper PL feature, with a peak at about 2.48 eV, which we attribute to Te-n greater than or equal to3 clusters as well as to corre sponding non-nearest-neighbors pairs.