Abstract
The low temperature photoluminescence spectral lineshape of the free exciton in undoped bulk GaAs, a broad weak doublet whose shape is commonly assumed a consequence of intrinsic processes, is experimentally demonstrated to be of extrinsic origin. In particular, the doublet shape is associated with the presence of residual donor impurities. A model, based on elastic scattering from neutral impurities and incorporating the polariton nature of the exciton, was developed. The excellent agreement between the model calculations and the experimental spectra demonstrates the importance of scattering processes on exciton-polariton transport. This model is applicable to any material with a dipole active exciton and may account for the structure observed in the lineshapes of free excitons in other compound semiconductors which have previously been attributed to other mechanisms.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
