Abstract
The well-width dependence of the binding energy () of excitons to neutral donors in high-quality, narrow, pseudomorphic As/GaAs single-quantum-well structures was obtained via low-temperature photoluminescence measurements. It is observed that varies smoothly with well widths for wells that vary from two monolayers (5.7 Å) to ten monolayers (28.5 Å) in width. The results are understood on the basis of simple physical arguments. Additionally, a previously unobserved transition was found for both undoped and donor-doped, two-monolayer-wide As/GaAs quantum wells. This transition is identified with a bound-to-bound transition and is shown to have a significantly faster time-resolved photoluminescence response than those of both the heavy-hole–free-excitonic and neutral-donor–bound-excitonic transitions.
- Received 19 December 1990
DOI:https://doi.org/10.1103/PhysRevB.44.1839
©1991 American Physical Society