Abstract

Similar to epitaxial quantum wells, colloidal quantum wells display electron intersubband transitions when photoexcited or electrochemically charged. Compared to epitaxial quantum wells, the strong confinement effect of thin, monodisperse colloidal quantum wells results in narrow intersubband transitions which reach high energies spanning the near-infrared spectral range. The composition of surface ligand chemistry subtly tunes the strain of the colloidal quantum wells to generate intersubband transitions over nearly continuously tunable energies. The divergent behavior of the band gap energy and intersubband transition energy implicates a substantial role of biaxial (in-plane) strain on the valence band structure. Multiple pump transient spectroscopy was furthermore employed to examine the lifetime of intersubband transitions, which is critical to their implementation in quantum cascade lasers or infrared detectors. In all cases, including core/shell samples, the lifetime of intersubband transitions is limited by surface or LO phonons to 1 ps or less, much shorter than comparable intraband transitions in quantum dots.

Full Text
Paper version not known

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.