SIMPLIFIED CALCULATIONS OF BAND-GAP RENORMALIZATION IN QUANTUM-WELLS

Non-linear optical properties of photoexcited semiconductor quantum-we lls are of interest because of their opto-electronic device applicatio n possibilities. Many-body interactions of the optically created elect rons and holes lead to the band-gap renormalization which in turn dete rmines the absorption spectra of such systems. We employ a simplified approach to calculate the band-gap renormalization in quantum-well sys tems by considering the interaction of a single electron-hole pair wit h the collective excitations (plasmons). This method neglects the exch ange-correlation effects but fully accounts for the Coulomb-hole term in the single-particle self-energy. We demonstrate that the density, t emperature, and well-width dependence of the band-gap renormalization for GaAs quantum-wells within our model is in good agreement with the experimental results. (C) 1996 Academic Press Limited