Quantum well

About: Quantum well is a research topic. Over the lifetime, 44627 publications have been published within this topic receiving 674023 citations. The topic is also known as: QW & quantum potential well.

Evaluation of the fundamental properties of quantum dot infrared detectors

Abstract: The physical properties of detectors based on intraband optical absorption in quantum dots is described and examined in the interest of providing a competitive alternative infrared (IR) detector technology. These quantum dot detectors are an extension of quantum well infrared photodetectors and are expected to have a large performance advantage. A model is developed for quantum dot infrared photodetectors based on fundamental performance limitations enabling a direct comparison between IR materials technologies. A comparison is made among HgCdTe, quantum well, and quantum dot IR detectors, where quantum dots are expected to have the potential to outperform quantum wells by several orders of magnitude and compete with HgCdTe. In this analysis, quantum dots are expected to possess the fundamental ability to achieve the highest IR detector performance if quantum dot arrays with high size uniformity and optimal bandstructure may be achieved.

Room temperature polariton lasing in a GaN∕AlGaN multiple quantum well microcavity

Abstract: The authors report room temperature polariton lasing at λ∼345nm in a hybrid AlInN∕AlGaN multiple quantum well microcavity (MQW-MC) containing a GaN∕AlGaN MQW active region, i.e., the achievement under nonresonant optical excitation of coherent light emission of a macroscopic population of polaritons occupying the lowest energy state of the lower polariton branch. This was made possible by taking advantage of the efficient relaxation of polaritons in a MQW-MC exhibiting a large vacuum Rabi splitting ΩVRS=56meV.

Phase-controlled currents in semiconductors.

Abstract: The direction of emission of photoexcited electrons in semiconductors is controlled by adjusting the relative phase difference between a midinfrared radiation and its second harmonic. This is achieved by using quantum interference of electrons produced with one- and two-photon bound-to-free intersubband transitions in AlGaAs/GaAs quantum well superlattices.

Well-resolved band-edge photoluminescence of excitons confined in strained Si1-xGex quantum wells.

Abstract: We report the first well-resolved band-edge luminescence from excitons confined in fully strained SiGe quantum wells grown on Si. At liquid-He temperatures the photoluminescence is due to shallow bound excitons, and in addition to a no-phonon line, phonon-assisted transitions involving TA phonons and Si-Si, Si-Ge, and Ge-Ge TO phonons are observed At higher temperatures the spectra are dominated by free-exciton luminescence. Quantum-confinement effects shift the observed free-exciton edge above the bulk strained band-gap energy, and also influence the relative intensities of the three TO-phonon replicas.

Electric-field dependence of linear optical properties in quantum well structures: Waveguide electroabsorption and sum rules

Abstract: We summarize the electric-field dependence of absorption and luminescence in quantum wells for fields perpendicular to the layers, present extended discussion of electroabsorption spectra and devices in waveguide samples, and derive sum rules for electroabsorption. Optical bistability, self-linearized modulation, and optical level shifting are demonstrated in self-electrooptic effect device configurations, with good modulation contrast and polarization-dependent properties. The electroabsorption spectra enable quantitative comparison of theory and experiment for absorption strengths in quantum wells with field. The sum rules enable excitonic effects to be included in the comparison, and good agreement is seen. One sum rule is also more generally applicable to electroabsorption in semiconductors.