Abstract

Localized exciton energy relaxation in three undoped lattice mismatched Al0.35Ga0.65As/GaAs1– y P y strained quantum wells (QWs) has been investigated by using picosecond time-resolved photoluminescence (PL) spectroscopy. The well widths (LZ) for two QWs with y = 0.05 are 121 Å (QW-A) and 79 Å (QW-B). Another QW (QW-C) is LZ = 121 Å with y = 0.08. QW-C is more strained. For these structures, the lowest energy excitons are degenerate exciton, heavy exciton, and light exciton in QW-A, B, and C, respectively. We have evaluated the time varying average exciton energies <E(t)> for the QWs from the time-resolved PL spectra. The <E(t)> decreased exponentially with time. Using the exciton masses and exciton deformation potentials (DP) determined by linearly interpolating the values for GaAs and GaP, we have obtained excellent agreement in QW-A and B between <E(t)> data and the theoretical curves. The relaxation rate is confirmed to be proportional to the square of the product of exciton mass and DP and to be inversely proportional to LZ. For QW-C, the energy relaxation rate is between the light and the heavy exciton relaxation rate. This indicates that the exciton in QW-C relaxes because of not only acoustic DP interaction but also because of other scattering mechanisms.

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

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.