CONFINED EXCITONS IN SEMICONDUCTORS - CORRELATION BETWEEN BINDING-ENERGY AND SPECTRAL ABSORPTION SHAPE

We calculate excitonic absorption spectra in several types of semicond uctor nanostructures by using an original formalism involving fraction al-dimensional spaces. This compact, analytical formulation predicts a surprising one-to-one mapping between the enhanced exciton Rydberg an d the shape of the spectrum, whatever the physical origin of the confi nement. by all-numerical calculation of the optical susceptibility we check that different systems with identical exciton Rydbergs exhibit n early identical spectra, strikingly close to those given by the fracti onal-dimensional approach.